diverticula get less and less marked until we arrive at the apex, which is quite smooth. These diverticula are the claw-shaped protuberances" of Mr. Hudson, and this descriptive term was by no means badly chosen; each diverticulum tapers towards its extremity and is bent inwards, thus assuming a decidedly claw-like shape.

The appearance of the interior of the cæcum is illustrated in fig. 3, p. 65, and is not by any means unlike the reticulum of a ruminant's stomach. Each of the diverticula is marked off by a raised valvular ridge. Towards the apex of the cæcum, where the diverticula are less prominent as such, the valvular ridges are quite as well marked as they are posteriorly; they are, indeed, rather more conspicuous, though this is not very well shown in the figure, which, however, represents the cæcum flattened out. An interesting peculiarity about these valvular projections is, that towards the apex those running transversely, or nearly so, to the long axis of the cæcum get to prevail over those running longitudinally. The effect of this is to produce a spiral arrangement, and the last inch of the cæcum (at any rate in one specimen, where it was very obvious) was marked by a simple spiral valve, all trace of the connecting ridges marking the surface out into areas having vanished.

There is here an interesting resemblance to the Ostrich *, which may possibly be more than a mere superficial likeness. In any case the remarkable form of the cæca of Calodromas elegans is due to the presence of these valve-like folds, which produce constrictions on the outer surface, between which the cæcum tends to bulge out. Posteriorly the intervals between the folds are so greatly produced into external protuberances that, until a dissection is made, one is tempted to regard the protuberances as regular diverticula of the cæcum, which they are, strictly speaking, not, any more than the intervals between the spiral valve of the Ostrich's cæcum, or the sacculations of the mammalian cæcum. It is perhaps a little difficult to make such a distinction, but I regard the folds as having appeared first and as having, in a way, caused the appearance of the diverticula.

*See Sir Everard Home, Comparative Anatomy,' vol. i.

VII. Notes on the Island of Palma in the Canary Group. By H. B. TRISTRAM, D.D., F.R.S.

(Plate III.)

MR. MEADE-WALDO concludes his interesting paper in the last 'Ibis,' on the "Birds of the Canary Islands," by expressing his surprise that he has found so much to tell after all that has been written upon them. I can only follow him by the confession that I feel he has exhausted the subject, and that were it not for the imperative order of our Editor, I should not have ventured to take up my pen. The island of Palma certainly claims especial notice at the hands of the ornithologist, from its peculiar features, from what it does possess in the way of bird-life, and from what it does not possess. The peculiarities of the avifauna of Fuerteventura and Lanzarote may be easily explained by the fact that they are, if not geologically (for they are as purely volcanic in their orizin as the other members of the Canarian group), yet biologically simply western outliers of the Great Sahara, and have derived their forms of life from there across the narrow sea which separates them from the African coast. The comparatively low elevation of the volcanic rim which girds each of these islands, and which rarely rises above 2000 feet, has forbidden the growth of the evergreen forest which crowns, or has crowned, the heights of all the other islands above 3500 feet. This has acted and reacted by attracting the cloud-belt which always hangs on their north and northeastern sides, securing plentiful supplies of water, and nourishing the forests, which thus attract and sustain a rich variety of animal and vegetable life. Consequently in Fuerteventura for certain, and in Lanzarote, so far as we know, there is no trace of what we may term the peculiar Canarian Avifauna. The Houbara Bustard, the Courser, the Trumpeter Bullfinch, the Sandgrouse are all manifestly immigrants from the Sahara. Mr. Meade-Waldo's new Chat (Pratincola dacotia) is certainly, so far as we know, peculiar; but we must bear in mind the fact that the opposite coast of

Africa is unexplored, and that quite possibly the scanty scrub of the African coast-line is its true motherland.

There is, however, one bird of Fuerteventura which deserves special notice, the Titmouse, rightly designated by Mr. Meade-Waldo Parus ultramarinus, though it seems to be invariably smaller than any Algerian specimens, and generally to have a broader white band on the forehead. We may easily trace its passage from the southern shores of the Mediterranean along the western coast-line of Morocco, till it crossed the narrow sea to Fuerteventura. Here it has remained unmodified, excepting for its slightly smaller size, a result not to be marvelled at in the barren desert plains and bare wadys of the island, with such scanty scrub as to render it difficult for even a Titmouse to find sustenance. Indeed, were it not for the occasional patches of cultivation, with a few palms and fig-trees, I do not see how the bird could long survive. But when crossing from the south end of Fuerteventura, it took up its abode in the wooded islands of Canaria, Tenerife, and Gomera, with their magnificent belts of evergreen forests, it found abundant food, and attained the full size of its Algerian progenitor, with a much darker back, and it lost entirely the white tips to the wing-coverts, which neither Mr. Meade-Waldo nor I have ever detected in a single specimen from any of the three above-mentioned islands. In another respect the Tenerife Tit differs from that of Palma. It is found in all localities and situations from the shore to the desolate cumbres, 5000 feet above the sea. It is equally at home on the house-roofs of Orotava, the gardens of country-houses, the evergreen forests, and the naked cliffs on the summit of the Paso del Croce of Canaria. Not so, as Mr. Meade-Waldo has shown, the Parus palmensis. I am certainly unable to explain why there should be such a contrast in several respects between the avifauna of Palma and that of its close neighbours, while these only differ among themselves in the presence or absence of certain species caused by the intervention of man.

Palma is, to me, the most attractive member of the Canary group. Though more affected by human colonization than

Gomera, it possesses greater natural variety of soil and scenery and has some unique features. On the map it is laid down pear-shaped, with the narrow end pointing due south. As we approach it from the east its profile is again exactly like a pear, a bold round mountain-mass, with precipitous sides, but gradually sloping from the neck till its southern point is lost in the sea. Closer examination explains very simply this formation. Originally a circular volcanic mass of 7600 feet in height, with a central crater, Palma must have been a larger edition of what the far more ancient Gomera is to-day. During some convulsion the lava burst through the southern side of the crater, and poured forth its stream into the sea, thus forming the neck of the pear, and leaving in the centre of the island a vast hollow cup, known as the Caldera, or caldron, 7 miles in diameter from north to south, and 5 from east to west, with its inner sides sometimes 5200 feet deep, and that an absolutely sheer precipice, the bottom of the Caldera being 2400 feet above the sea-level. On the north-west of the island there is no available anchorage, even for the smallest craft; while the only anchorage on the east is a partially sheltered roadstead, with a small artificial harbour, at Ciudad de Santa Cruz. This is the metropolis of the island, and one of the best and most interesting cities of the whole Canary group, with a noble ancient church, and a handsome town-hall erected by the Emperor Charles V. There is a thoroughly old-world air about the place, with its clean streets, running one above the other, parallel to the shore, very much like a miniature Funchal, its well-stored and attractive-looking shops, and the quaint and bright costumes of both men and women, indicating at once whether they hail from the north-west or south of the island. There is a comfortable Spanish fonda, but foreign visitors are rare. Only one did we meet with an intelligent and cultured Bavarian physician, bent on investigating the hygienic character of the country. There is no consul or consular agent, and until this year, when for the first time the interinsular steamers call once a week, thanks to the enterprise of Messrs. Forwood, Brothers, there

was no communication with the outer world, save by wretched little schooners; and the only trade of any importance was that with Havana, chiefly consisting in the export of onions. Happy, bright, rather lotus-eating, troubled for the most part with neither poverty nor riches, the people of Palma might be taken for lineal descendants of the cultivators of the garden of the Hesperides.

The land rises steeply from the shore at Santa Cruz de Palma or, as it is universally called there, La Ciudad, and a finely engineered road, the only one of the kind in the island, zigzags up the hill for several miles, affording magnificent views at every turn, and then runs southwards through a sloping plain to Buenavista. Everywhere the land is carefully cultivated from the shore upwards. Every kind of fruit, from the pine-apple and orange to the cherry and the plum, thrives at one elevation or another. One of the staples of the island is a fine quality of silk, grown, spun, dyed, and woven on the spot; its cigars pass as the choicest Havanas ; and its wines are the best in the Canaries. What can a reasonable man desire which he may not find in Palma? And besides, there is or, perhaps I should say, there was, till yesterday, a chance of discovering a new species of bird. This latter, however, was not one of our pleasures of anticipation when we landed at Ciudad, though it was the most agreeable of the pleasures of surprise. We inquired after local naturalists on our arrival, but without success. ever, in a country where visitors are few, news spread quickly, and soon we had a call from one gentleman who had been collecting the Lepidoptera of the island, and who brought his collection to show to us; and from another, the editor of the local paper, who was really a botanist, and brought some specimens of a local subalpine plant (Viola palmensis), which only grows, at a height of 7000 feet, in two spots, where, from his information, we afterwards found it.

How

Our first day's expedition was to an evergreen forest, some four miles N.W. of Ciudad, where we had reason to believe we should meet with the "Turqueze" Pigeon, whatever species it might be. The first part of our ride was rugged and