April 27, 1905] 



NA TUR.E 



615 



To the April number of the Journal of Anatomy and 

 Physiology Dr. A. Keith contributes a thoughtful article 

 on the nature of the mammalian diaphragm and pleural 

 cavity. The pleural cavity he considers to have been formed 

 by a hernia-like outgrowth from the general body-cavity, 

 the diaphragm thus being formed by a portion of the 

 original outer wall of that cavity. Considerable interest 

 also attaches to a paper by Dr. A. A. Gray on the mem- 

 branous labyrinth of the internal ear of man and the seal, 

 in the course of which it is shown that seals possess in 

 this region large otoliths comparable to those of fishes. 

 Although the precise function of these structures is at 

 present unknown,- it would appear from their occurrence in 

 the two groups that they are correlated with an aquatic 

 existence. 



In the second of a series of articles on Canadian life, 

 published in the April number of the Empire Reiiiew, 

 Mr. A. P. Silver, of Halifa.K, gives a graphic description 

 of the wild, or " feral," horses inhabiting in large droves 

 the storm-swept Sable Island. This island, which lies 

 about eighty miles to the eastward of Nova Scotia, consists 

 of an accumulation of loose sand, forming a pair of ridges 

 united at the two ends and enclosing a shallow lake ; tracts 

 of grass are to be met with in places, as well as pools of 

 fresh water. The droves of wild horses, or ponies, and 

 herds of seals appear to be the chief maijimalian in- 

 habitants of the island. It is generally supposed that the 

 original stock was landed from a Spanish wreck early in 

 the sixteenth century, although some writers make the 

 introduction much later. Five-and-twenty years ago the 

 number of ponies was estimated at between 500 and 600 ; 

 at the present day there are less than 200, divided into 

 five troops. Not more than two-thirds of these are pure- 

 bred, the remainder being the offspring of mares crossed 

 with introduced stallions. The introduction of these 

 foreign stallions (which is to be regretted by the naturalist) 

 has been a matter of great difficulty, as the strangers 

 were attacked and wounded by the leaders of the droves. 

 The author comments on the striking likeness of these wild 

 ponies to the horses of the Parthenon frieze and to the 

 now exterminated tarpan of Tartary. They also seem to 

 respmble the wild horses of Mexico, although their coat 

 is doubtless longer. These resemblances seem to point to 

 reversion to the primitive type of the species. All colours 

 save grey characterise the pure-bred stock ; but chestnut, 

 with a dark streak on the back and on the withers, is the 

 most common tint, after which come bays and browns. 



Prof. H. F. Osborn has been good enough to send us 

 a collection of papers published by himself during the past 

 year, some of which have been already noticed in our 

 columns. Among the latter is one on a re-classification of 

 reptiles, from the American Naturalist of February, 1904, 

 in which it is proposed to divide the class into the brigades 

 Diapsida and Synapsida. This plan is further elaborated 

 in part viii. of the first volume of the Memoirs of the 

 American Museum, which is well illustrated, and gives 

 the leading characteristics of a number of the chief groups. 

 The budget also includes three papers from the Bulletin 

 of the American Museum, one dealing with sauropod 

 dinosaurs, the second with new Oligocene representatives 

 of the horse line, and the third with armadillos from the 

 Bridger Eocene. An interesting feature recorded in the 

 first of these is the discovery that in some at least of the 

 sauropod dinosaurs the first digit of the fore-foot was alone 

 furnished with a claw, or, at all events, with a claw of 

 large size. The discovery of what are regarded as ances- 

 tral armadillos (apparently furnished with a leathery skin) 

 NO. 1852, VOL. 71] 



in the Bridger Eocene is of much interest from a distri- 

 butional point of view. It is noteworthy that these animals 

 were described under the name of Metacheiromvs, under 

 the impression that they were allied to the aye-aye 

 (Chiromys). 



In a communication published in the American Journal 

 of Science for April, 1904, Prof. Osborn summarises the 

 palffiontological evidence in favour of the theory that 

 mammalian teeth are derived from a primitive tritubercular 

 type, and comes to the conclusion that it strongly supports 

 the theory. Reference may also be made to the preface 

 to vol. ii. of the Bulletins of the American Museum (1898- 

 1903), in which Prof. Osborn gives an interesting account 

 of the explorations and researches carried out by the de- 

 partment of vertebrate paleontology during that period. 

 Special endeavours have been devoted to collecting the 

 dinosaurian remains from the Upper Jurassic of Wyoming 

 and Colorado. 



.•\ CAT.iLOGUE of second-hand books in various branches 

 of botany, offered for sale by Mr. F. L. Dames, Berlin, 

 has been received ; the sections best represented are the 

 diatoms and desmids, floras, and the works on anatomy 

 and physiology. 



.^N abridged report on the experiments with seedling and 

 other canes in the Leeward Isles in 1903-4, forming No. 33 

 of the pamphlet series of publications of the Imperial 

 Department of Agriculture for the West Indies, shows a 

 certain amount of divergence from the results of previous 

 years in the list of canes arranged according to sugar 

 production ; Dr. F. Watts, the officer in charge, attributes 

 it to the dryness of the season. In Antigua, Sealy Seed- 

 ling, a cane of great vegetative vigour, appears first on 

 the list, while B 208, which still retains its character of 

 producing the purest juice, drops to the fourth place. A 

 system of comparing the plants according to the number 

 of stations in which they figure among the first seven 

 promises to determine those most suitable for general 

 planting. 



A FLORA of the Calcutta district, where the district ex- 

 tends sixty miles south and forty miles in other directions, 

 has been compiled by Dr. Prain, and is published as 

 vol. iii.. No. 2, of the Records of the Botanical Survey of 

 India under the title of the " Vegetation of the Districts 

 of Hughli-Howrah and the 24-Pergunnahs." The larger 

 part of the district is alluvial rice-country, but a dry area 

 occurs in the north-west, and the West Sunderbuns in the 

 south comprise swamp forest and muddy ci-eeks. The flora 

 is not confined to wild plants, but includes crops and trees 

 or shrubs of cultivation. The list of crops, with the 

 original home of each, brings out very clearly the varied 

 sources from which they are derived ; as compared with 

 fifty native plants, twenty-five are traced to the Mediter- 

 ranean area, and about twelve each to Africa and America, 

 besides other Asiatic species. 



Before vacating the post of Government mycologist in 

 Ceylon, Mr. J. B. Carruthers placed on record in the 

 Circulars (vol. ii., Nos. 28 and 29) of the Royal Botanic 

 Gardens his observations on two cankers, caused by species 

 of Nectria, on tea bushes and rubber trees respectively. 

 The tea canker which has been known in India for some 

 years was found over a large area of the tea districts, 

 more especially at the high elevations and on some of the 

 finest tea plantations ; the fungus spreads in the soft tissues 

 under the bark, but produces cracks where the spores are 

 formed. The Nectria on the Para rubber trees is more 



