1160 nioF. J. p. mix and mr. r. h. burne on the 



tlie\^ were larger and more easil}^ seen in specimen B than in 

 specimen A. They varied considerably in size, the largest 

 measuring 5'5 X 4"5 mm. in diameter, the smallest 1*5 mm. They 

 numbered about sixty, and were chiefly distributed upon the 

 parts of the chorion that overlay the head region of the foetus, 

 being more numerous on the right side than on the left. 



In specimen A, although a few of these bodies were as large 

 as in specimen B, the majority were no larger than a pin's head. 

 Most of them were located upon that part of the chorion which 

 occupied the left uterine horn, being particularly numerous upon 

 those areas where the chorionic laminae were most richly deve- 

 loped. Few, iF an}^, could be located with certainty on the 

 chorion within the right horn and the body of the uterus. 



In the sections (Pi. Y. figs. 13 & 14, ch.ves.), the vesicles ar'e 

 seen to be situated either in the allanto-chorionic connective 

 tissue, close to the allantoic lumen, or actually in that of the 

 laminar villi. The vesicle is of simple structure, and unlike those 

 of Nycticebus and Galago, is devoid of villous folds or ingrowths 

 projecting into its cavity. Its opening is small and slit-like (PI. V. 

 fig. 13, op.). Lining the cavity is a single-layered epithelium, 

 representing an involuted portion of the trophoblast, but differing 

 from that in its characters. It consists of low cubical to flattened 

 cells, -013 to "008 mm. in thickness. The cytoplasm of the cubical 

 cells is reticular in character, and encloses one or more laig'e 

 vacuoles. The nuclei are mostly basal in position, and frequently 

 appear shrunken and irregular. The lining rests on a very thin, 

 compact layer of fibrillar connective tissue. It is noteworthy that 

 the vesicle-wall appears to be entirely devoid of capillaries. The 

 cavity is occupied more or less completeh'- by a coarsely granular 

 coagulum, no doubt representing the secretion of the uterine 

 glands, and in it there occur, here and there, degenerating cells, 

 probably derived from the lining epithelium. 



The chorionic vesicles of Nycticehus and Galago described by 

 Hubrecht and Strahl are more highly differentiated than those 

 of Chiromys, and would seem to be specially adapted for the 

 collection and absorption of the secretion of the uterine glands 

 (Strahl, 14). In our sections of Nycticehus, we find the vesicle 

 invested externally in a fairly dense fibrous connective-tissue 

 coat, in which there are present numbers of laig-er and smaller 

 blood-vessels. The lining of the sac is formed by a flattened to 

 cubical epithelium, in contact with the under surface of which 

 there are here and there fair-sized capillaries. The cavit}'- of the 

 vesicle is largel}^ occupied by Avascular villi as described by 

 ITubrecht, clothed by an epithelium similar to that lining the 

 cavity, and between the villi is a granular material similar to 

 that found in the uterine glands. 



In Qalago, Strahl (14) described the occurrence of similar 

 vesicles, but found that their openings, unlike those of Nycti- 

 cehus, overlie depressed areas of the mucosa on which are the 

 openings of uterine glands. 



