1070 
DR. H. WATNEY ON THE MINUTE ANATOMY OF THE THYMUS. 
corpuscles, and the long threads forming the network. He considered that the thymus 
has a central thread, to which the lobules are attached; this thread consisting of artery, 
vein, lymphatic vessels, and central canal; that each acinus has a small hollow, and 
that all the hollows are in communication with a central canal. He gave figures 
showing the difference, in the follicle, between the cortical and medullary portions, 
drawing the latter as a dark round or oval space in the centre of the follicle ; he 
concluded that the dark spaces are the central hollows. (See his figs. 20 and 17.) 
He said that all the lymphoid corpuscles show a ring of protoplasm around the 
nucleus, if they are treated with five per cent, phosphate of soda. His noticed that 
there are cells with pigment granules and with great red spheres like blood corpuscles, 
and that the concentric corpuscles are connected with the small vessels, often surround 
them completely, or rest on their points of division. He noted that the lymphatic 
vessels are in close approximation to the wall of the follicle. He tied these vessels as 
they leave the thymus and concluded that the corpuscles travel by these paths, although 
he had never seen any communication between the central cavity and the lymphatic 
vessels. He considers that the thymic corpuscles are changed into blood corpuscles ; 
in describing the circulation he gave drawings of the thymus after it had been injected 
from the arteries and the veins, and found that the arteries run into the centre of the 
follicles, and ramify outwards, and that the larger veins are on the outside. 
Melchior (60), 1859, in his dissertation dealt chiefly with the pathology of the 
thymus. 
Turner (61), 1860, noticed a thymus in an adult Porpoise and in an adult Antelope. 
Hirzel and Frey (62), 1863, wrote on the hibernating gland. They noticed the 
fact that if these glands are exposed to the air they assume a dark red-brown colour. 
Kolliker (54), 1863, adhered in great measure to his former view. He described 
the star-shaped cell network in the follicles, and noticed large cells with multiple 
nuclei. He confirmed the fact observed by Hewson (10) and His (46), that the 
lymphatic vessels contain very many corpscules, similar to those of the thymus, and 
described the simple concentric corpuscles as having a granular mass in their interior; 
he did not think that they arise from the gland cells. 
Paulizky (49), 1863, compared the concentric corpuscles to the corpora amylacea. 
He adhered to the view that the elements undergo fatty degeneration. Paulizky’s 
drawings of the concentric corpuscles and of the granular cells are very good. He 
noticed, as Pemak (57) and Jendrassik (30) had previously done, that the concentric 
corpuscles are found in the central parts of the follicles; he thought that they are 
pathological formations, arising from epithelial cells ; these epithelial cells taking their 
origin from small round cells. He described and figured the vacuolation of the 
granular cells. 
Toldt (63), 1868, examined the thymus of Amphibia; he gave drawings of peri¬ 
vascular spaces around the vessels in the thymus of the Salamander. 
Klein (32), 1870, noticed cellular elements in the capsule. He stated that there 
