196 FRANCIS H. A. MARSHALL. 
not become entirely spent in the formation of the inter- 
epithelial connective tissue. V6lker finds also in unruptured 
atretic follicles lutein cells which are similar to those of 
discharged follicles. 
Two authors who have recently written on thts formation of 
the corpus luteum reject Bischoff’s theory, on what substantial 
grounds I find it difficult to understand. Of these, Jankowsky 
bases his opinions on the study of a miscellaneous collection 
of material obtained mostly from the sow, but without any 
attempt at systematic investigation. The few figures which 
this author gives do not seem to me in any way opposed 
to the follicular epithelial theory, while the figure of the 
developing corpus luteum from the guinea-pig appears rather 
to support the hypothesis that the hypertrophied cells arise 
from the membrana granulosa, and the anastomosis between 
those cells from the tissue of the theca. Jankowsky’s view is 
largely based on the appearance of “lutein cells ”’ in the theca 
interna prior to the rupture of the follicle. 
Williams, in a recent work on obstetrics, takes up the 
same position as Jankowsky, partly on the ground that “the 
membrana granulosa presents extensive degenerative changes, 
and is usually cast off in great part at the time of rupture,” 
and partly because the cells of the theca interna undergo 
marked changes during the follicle’s development, and 
eventually come to resemble lutein cells. The former state- 
ment, indeed, is very far from being proved, while the latter 
appears to me to be singularly inconclusive. Williams 
argues also that the degenerative changes which have been 
observed in the epithelium of atretic follicles afford evidence 
that similar changes occur in discharged follicles. ‘ Obser- 
vations based upon the study of several hundred human 
corpora lutea have convinced me that the connective tissue 
origin of the lutein cells is established beyond all reasonable 
doubt.” Williams, however, does not say that these speci- 
mens have been described in any published paper, and, in 
the absence of the evidence, I am unable to regard his 
Opinion as in any way conclusive. 
