574 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
corpora lutea. Further, the distinction between corpora lutea vera and 
spuria is entirely fictitious, the two being wholly similar structures. 
The corpus luteum originates from the membrana folliculi interna. 
In the same place M. Honore * details some observations on the same 
subject in the rabbit. In essentials his observations agree with those of 
Sobotta, but differ from them in some minor points. He finds that at 
the time of the rupture of the follicle the membrana interna is intact, 
and the yellow cells of the corpus luteum arise from the modified epi- 
thelial cells of this membrane. iSo far he is in perfect agreement with 
Sobotta ; but, while the latter believes that the whole of the interstitial 
cells of the internal theca are converted into the connective-tissue ele- 
ments of the corpus luteum , Honore finds that a part only are so modified 
and a part persist for some days as little islands of cells between the 
theca externa and the yellow cells. The capillaries of the corpus 
luteum originate from the vessels of the old theca interna , in part by 
budding, and in part by giving off vaso-formative cells. The haemor- 
rhage at the rupture of the follicle is due to the tearing of the vessels of 
the internal theca. 
H. Doesing | contributes the results of his study of the ovary of 
the sow. He finds that the epithelium of the follicle wall is disrupted, 
and plays no part in forming the corpus luteum. This arises from the 
modified elements of the theca interna, and is therefore entirely a con- 
nective-tissue structure. 
Cell-division in the Mammalian Ovary. — Dr. Hans Babl J has in- 
vestigated an ovary removed from an adult, which, like a previous pre- 
paration of Dr. Stoeckel’s,§ seemed to show the formation of new ova in 
adult life. Stoeckel found multinucleated ova and also follicles containing 
several ova. He stated that the nuclei of the multinucleated ova arise 
by direct nuclear division, and that the follicles containing two or more 
ova become divided into two or more new follicles. Rabl’s preparation 
was better fixed than that of Stoeckel, and enabled him to draw the fol- 
lowing conclusions. He agrees with Stoeckel that the follicles with 
several eggs arise from the multinucleated eggs, that the follicles do not 
persist in this condition, but, by an ingrowth of the follicular epithelium 
become converted into several new follicles, and that in his own case 
and Stoeckel’s this occurs in adult life. He disagrees however from 
Stoeckel in regard to the origin of the nuclei. He finds no proof that 
they are the result of direct nuclear division, but believes that the 
multinucleated eggs are eggs formed during foetal life, which, owing to 
the pressure of the surrounding tissues, have been crushed together, and 
only separate in later life. 
Fertilisation Phenomena in Lamprey. ||— Dr. Karl Herfort publishes 
a short account of his observations on the union of the pronuclei in the 
egg of Petromyzon fluviatilis. At the time when the uuion occurs, two 
rounded structures lie at the poles of the conjugating nuclei. Each 
consists of a darkly staining granule surrounded by an alveolar layer 
* Anat. Anzeig. (Erganzungsheft), xvi. (1899) pp. 34-8. 
f Op. cit., xvi. (1899) pp. 299-301 (1 pi.). 
X Arch. Mikr. Anat., liv. (1899) pp. 421-40 (1 pi. and 1 fig.). 
§ Zeitsckr. f. Geburtshiilf. u. Gynakol., xxxix. 
|| Anat. Anzeig., xvi. (1899) pp. 369-76 (5 figs.). 
