1110 
DR. H. WATNEY ON THE MINUTE ANATOMY OF THE THYMUS. 
Fig. 19. Camera lucida, obj. 7, X 450, oc. HI., obj. 9. 
Teased specimen of thymus of Calf one year old. 
Ic. Lymphoid corpuscles. 
b. Coloured blood corpuscles. 
c. and d. Cells containing haemoglobin granules. 
Fig. 20. Camera lucida, obj. 7, X 450, oc. Ill, obj. 8. 
Teased specimen of thymus of Calf seven months old. 
c. d. Cells containing haemoglobin granules. 
Fig. 21. Oc. III., obj. 8, X 400. 
Teased specimens. 
a.b.c. From thymus of Dog one year old. 
d. From thymus of Calf twenty days old. 
The cells contain spherules, and masses of haemoglobin, some of them as 
large as the coloured blood corpuscles. 
Fig. 22. To illustrate the colours of the haematoxylin staining solutions. 
They were all made with potash alum and extract of logwood, in the 
proportion of three to one. 
(a) . With old powdered alum. 
(b) . With old crystals of alum. 
(c) . With old alum. (This solution had been made four years, all the 
others only a few hours.) 
( d ) . With old dried alum. 
(e) . With fresh crystals of alum. 
(f) . With freshly-made dried alum. 
Fig. 23. Camera lucida, obj. 2, x 75, oc. III., obj. 4. 
Transverse section of one-half of the thymus of human foetus six to ten 
weeks old. 
Only about one-third of the drawing is filled in. 
There is no difference traceable between the medullary and cortical tissue. 
ct. Connective-tissue surrounding the gland. 
v. Blood vessels. 
The lympboid cells are drawn a little too small. 
Fig. 24. Natural size, represents three lobules of the thymus of Calf seven months 
old. Separated after the tissue had lain for some hours in dilute bichromate 
of potash. 
Figs. 25 and 26. From the cortex of follicle of the thymus of Calf twelve days old. 
In fig. 25, the specimen was shaken very carefully; in fig. 26, roughly for 
a long time. 
Fig. 25. Camera lucida, obj. 7, X 450, oc. III., obj. 8. 
c. Capsule with the blood vessels running obliquely through it. 
th. Strong threads. 
