107 



33 sections (of twelve ticks of the Cambridge microtome), and its 

 fibrous capsule proved on careful examination to be a seminiferous 

 tubule (cp. Latter, 9, and Miteophanow, 13), with a distinct cellular 

 structure at one point, at which point it contained a large number 

 of motile spermatozoa. Although some other parts of the tubule 

 showed traces of cellular structure, it for the most part consisted of 

 fibrous tissue probably representing the basement membrane of the 

 normal seminiferous tubule. The ovum was connected with the tubule 

 by two protoplasmic strands. The nucleus, which, excepting that it 

 stained slightly more deeply, was indistinguishable from the cytoplasm, 

 had so shrunk that it lay with one pole almost continuous with the 

 cytoplasm (Fig. 3 is a section through this part), whilst the other 

 was surrounded by a largish vacuole. There were no traces of 

 nucleoli. It seems to me that, from what is already known of the 

 degeneration of eggs in the frogs ovary, it is safe to conclude that 

 the above cell is 1) an ovum, and 2) in an advanced state of 

 degeneration. 



The general structure of the ovo-testis is even more interesting 

 than that of its solitary ovum (see Fig. 2), It is for the most 

 part made up of a mass of the polygonal pigment cells 

 which occur normally in the frog's ovary, with, however, 

 patches of normal testis at its poles. The anterior pole consists of 

 testis with a thin zone of the pigment cells invading one side, whilst 

 the posterior pole is somewhat over half testis. The remainder of 

 the gland is occupied practically by the pigment cells alone. Further, 

 a horizontal section through the middle of the gland of this side ex- 

 posed five circular spaces in the pigment mass, containing, surrounded 

 by fibrous capsules, spherical masses of lightly pigmented granular 

 matter. Three out of the five completely filled their respective spaces 

 — the other two did not; one of the latter also containing a large 

 vacuole. The significance of these bodies, which may be free and lie 

 indiscriminately among the pigment cells, and of the abnormally deve- 

 loped pigment mass, is of course on the available data impossible to 

 determine. The former may plausibly be looked upon as disinte- 

 grated ova * ) — the latter as preceding the development of ova and 

 the formation of a true ovo-testis (see Marshall, Fig. 12). 



1) Prof. Howes has added to his many kindnesses that of pointing out 

 what these bodies are. It is undoubtedly a case of resorption — a sub- 

 ject which has been admirably elucidated by Ruge in Siredon and 

 ISalamaudra ("Vorgänge am Eifollikel der Wirbeltiere", Morph. Jahrb., 

 Bd. 15, 1889, p. 491). Euqe's ova F, G, Hin Fig. 1, and also the 



