1064 
DR. H. WATNEY ON THE MINUTE ANATOMY OF THE THYMUS. 
Page 
The so-called hibernating glands. 1103 
Hemoglobin contained in cysts and in colourless cells. 1103 
The lymphoid cells oe the thymus, when examined in the fresh state. 1104 
Characters of the lymph and blood issuing from the thymus. 1104 
Physiological conclusions . 1105 
Explanation of plates. H07 
References.,... 1119 
The following research was begun in the year 1876, and has been carried on at 
intervals since that time. 
"We will first give the result of this research in a brief preliminary statement; secondly, 
the history of the subject; and finally, a detailed account. 
Preliminary Statement. 
I- —The cortex is the more important and essential part of the follicle of the thymus. 
In the cortex there are two hinds of retiform tissue—one (with small meshes ), which we 
call a reticidum, formed of fine fibres ivith thickened nodal points; and the other, 
which ive call a netivork, composed of branched connective tissue corpuscles. 
II- — The formation of connective tissue and of new vessels occurs chiefly by the agency 
of granular cells; these granular cells arise from connective tissue corpuscles, and there 
is great similarity between the formation of the connective tissue in the thymus, and in 
pathological new formations. 
III.— A concentric corpuscle usually arises, partially from the granular cells , and 
partially from the epithelioid connective tissue corpuscles; and the giant cells from either 
one or other of these sources. The concentric corpuscles are transformed into fibrous 
tissue. 
TV.—The connective tissue corpuscles in the thymus of the Dog can undergo certain 
changes, which finally transform them into ciliated epithelial cells. 
V. —In involution, the gland, diminished in size, though with enlarged blood-vessels, is 
transformed into connective tissue, and in Mammals is buried in fat. 
VI. — The thymus arises, in the embryo, in connective tissue. 
VII. — There are present in the lymph issuing from the thymus, cells containing 
coloured blood corpuscles and hcemoglobin granules; and in the lymphatics of the 
thymus there are more colourless cells than in the lymphatics of the neck. 
History. 
An account of the knowledge and speculations of the old writers is given very fully 
by Haugsted (1),* Simon (2), and Friedleben (3); consequently this part of the 
history is dealt with very shortly in this paper. 
* See the references, p. 1119. 
