60 DR. N. H. ALCOCE ON THE VASCULAR [Feb. 1, 



the arteries in several species, the vascular system has received but 

 scant notice. 



The recent observations on the morphology o£ blood-vessels, 

 especially those of Macalister ', Mackay ^, Hochstetter '\ and, 

 Young ■*, have given au increased interest to studies of the 

 vascular system ; and it was in the hope of adding to the sum of our 

 knowledge in this direction, even if only in a single order of the 

 Mammalia, that this paper was commenced. 



In the absence of any record of the general features of the 

 Vascular System in the Chiroptera, the simplest plan appeared to 

 be to describe as accurately as possible the arrangement in one 

 species, taking it as a type to which variations might be referred, 

 and this plan has been more or less adhered to in the following 

 account. Illustra,tions have been added from other species where 

 it appeared that the arrangement in Pteropus medius was unusual 

 in the order, and some additional notes on the thoracic organs 

 have been appended, when this seemed desirable for the sake of 

 greater clearness in description. 



The division of the Megachiroptera (Dobson) was selected on 

 account of the greater size of its members, and Pteropus medius, 

 the Indian Fruit-Bat, seemed a suitable representative '\ This 

 Bat is common in its native haunts — India — where it is found in 

 large flocks, which often cause much loss by devouring enormous 

 quantities of fruit, the voracity of these animals being apparently 

 only limited by the amount of time and fruit at their disposal *'. 



^ Macalister, A. — " The Morphology of the Arterial System in Man," Journ. 

 Anat. XX. 1886, pp. 



^ Mackay, J. Y. — " The Development of the Branchial Arches in Birds, etc." 

 Phil. Trans. Eoy. Soo. vol. 179 (1888), B. pp. 111-139, 4 pis. " The Arterial 

 System of Vertebrates Homologically considered," Proc. Phil. Soc. Glasgow, 

 xviii. 1887, and in Mem. of Anatom. vol. i. 1889. 



' Hochstetter, F. — " Ueber d. urspriingl. Hauptschlagader d. hint. Gliedm. 

 d. Menschen," etc., Morph. Jahrb. xvi. 1890, pp. 300-318, and " Ueber d. Entw. 

 d. Art. Vert. b. Kaninchen," loc. cit. pp. .572-586, and " Ueber den Ursprung der 

 Art. Subolav. der Vdgel," he. cit. pp. 484-493. 



* Young, A. H. — "The Termination of the Mammalian Aorta." Studies in 

 Anatomy. The Owens Coll. 1891, pp. 209-225, 1 pi., & Journ. Anat. xxxi. 

 pp. 169-175. 



° The dissection of the smaller vessels in Pteropus medius proved difficult 

 and tedious, although the body of this species is 8i inches long and the expanded 

 wings measure 3 feet across. The injection I found most suitable is the Lead 

 Chromate and Gelatine recommended by Hoyer (Arch. f. mikr. Anat. 1876, 

 p. 645), and quoted by BoUes Lee ( Micro tomist's Vade Mecum, p, 237), or 

 Hoyer's Shellac injection, coloured with very finely divided vermilion {/oo. cit. 

 1865, p. 149). I have found Von Graefe's cataract knife, modified by being 

 strengthened a little aloug the back and shortened in the blade, very convenient. 

 Some form of dissecting microscope is essential. 



^ Murray, J. A., Indian Annals, i. pp. 25-26, gives a description of this 

 species, and an account of the use of the flesh as medicine by the natives. See 

 also SiGEL, W. L., Zool. Garr. xxiv. (habits of P. medius in captivity) ; and 

 Day, F., Land of the Permauls, p. 4.39, who states that these Bats are very 

 partial to wild figs and almond-kernels, and also to cocoa-nut toddy. 



Beauregaud, H. — " Recherches sur I'oreille interne de la Roussette de I'lnde 

 (P. medius)," C. R. Ac. Sci. cxix. pp. 1351-1352. " Le Canal Carotid de 

 Ronssettes," 0. R. Biol. Paris, 1892, pp. 914-916. "Recberches sur I'appareil 



