354 



(18) had already expressed the opinion that it was probable that the 

 process of corpus luteum formation in D. viverrinus is the same 

 whether ovulation is followed by fertilization or not and an examina- 

 tion of the corpora lutea of several non-pregnant animals led to a 

 confirmation of this view. 



It was thought, however, that it would be of interest to examine 

 more fully the growth and structure of the corpus luteum in 

 the non- pregnant animal as there is a difference between the 

 corpora lutea in pregnant and non-pregnant females in some species, 

 e. g., Rabbit, etc. according to Ancel and Bouin ^ (1), and in some 

 cases the formation of this body is determined by the previous ocur- 

 rence of copulation. Also several points in connection with the 

 origin and composition of the corpus luteum are still matters for 

 discussion. It is further interesting because D. viverrinus, the Aus- 

 tralian native cat, is a marsupial and our knowledge of the various 

 phenomena connected with the reproductive processes in this group, 

 in certain respects more primitive than the Eutheria, is very slight. 

 Again the corpus luteum in the pregnant D. viverrinus has already 

 been accurately described by Saxdes (18), whose observations I have 

 f been able to confirm, and so forms a good basis for a comparison 

 between the corpus luteum verum, i. e., that of the pregnant animal 

 and the corpus luteum spurium, i. e., that in cases where ovulution 

 has not been followed by pregnancy. 



My thanks are due to Professor J. P. Hill for the material made 

 use of in this investigation, for much valuable data regarding it and 

 also for placing at my disposal the original slides made by Dr. Saxdes, 

 and now in his possession. 



Material. 



The material employed consisted of a number of ovaries of 

 D. viverrinus preserved in various fixing fluids, those fixed with 

 Picro-corrosive-acetic acid being in the best state of preservation. 

 In most cases there was with each ovary a record of the animal for 

 some time previous to killing. The ovaries were studied by means 



1) These authors propose to replace the terms corpus luteum verum, 

 and corpuß luteum spurium by gestative corpus luteum (corpus luteum 

 gestatif) and periodic corpus luteum (corpus luteum periodique) respectively. 

 The reasons they put forward however, do not appear strong enough to 

 justify this change and in the present paper the old terms are retained and 

 used with the same significance as in Sandes' paper. 



