1902.] CARPAL ORGAN IN HAPALEMUR GRISEUS. 163 



like the reticular tissue of a lymphatic gland. The laxity of this 

 tissue accounts for the fatty texture which the gland exhibited 

 on dissection. Imbedded in this reticular mass are the tubes of 

 the glands proper. The directions of these, as will be seen from 

 the drawing referi-ed to, is mainly across the shoit axis of the 

 gland. They run, however, in various directions. The tubes 

 are on the whole of much the same width throughout ; but the 

 calibre varies slightly from place to place. They are lined by a 

 layer of low columnar epithelium, and outside of this is a layer 

 of muscular fibres. The glandular tubes in fact conform to 

 the plan of gland exhibited by the sweat-glands of mammals. 

 They do not belong to the sebaceous type. The course is not 

 straight or even approximately so ; the glands are coiled in much 

 the same way which characterizes other sudoriparous glands, and 

 one can occasionally notice the characteristic undulations of these 

 glands. I could not observe anywhere any evidence of the 

 branching of the glands, and if it occurs it is at least not common ; 

 each separate tube appeared to be absolutely free of its neighbours. 

 Nor could any common duct be observed by which the sum total 

 of the separate glands opened on to the exterior. When a section 

 across the arm-gland was examined by a loAV-power lens, the 

 adenoid tissue was seen to be massed into strands lying to a 

 considerable extent parallel like the leaves of a book ; the direction 

 of these sti^aiids was mainly in the same plane as the two lateral 

 surfaces of the gland-mass and the two ends of the same. But 

 the strands are not entirely unconnected with each other. A 

 much thinner, laxer, tissue connected them to each other. But 

 very frequently the thinness of this led to its being missed through 

 injury or mere insignificance in a given section. It is in the 

 thick plates only that the gland-tuhes are to be seen ; they do not 

 occur in the much laxer between-tissue. The arm-gland, there- 

 fore, of this Lemur appears to present a possible stage in the 

 evolution of a compound gland out of an aggregation of separate 

 sudoriparous glands. It is very comparable to the milk-gland, 

 only that that gland (save in the Monotremes) is an aggregation 

 of sebaceous glands. If the laxer connective tissue lying between 

 the thicker plates were to vanish, and the gland-tubes, being 

 more closely approximated, acquire a connection with each other, 

 a compound gland would result. The external appearance of the 

 gland, as already stated, and as a23parent in the drawing exhibited 

 herewith (text-fig. 34, p. 161), is quite that of a compound gland, 

 and does not at all suggest a merely close approximation of 

 separate gland-tubes. The prevalence of the framework of the 

 gland over the gland-tubes is a very striking feature of this 

 arm-gland. 



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