4 04 SCIENCE PROGRESS 



after successful insemination, a fact which eliminates certain 

 of the difficulties encountered in a number of other species. 

 The author holds that the final maturation of a group of follicles 

 is induced by the material produced in preceding groups of 

 follicles which do not attain maturity. Upon reaching maturity 

 it is suggested that the follicles produce a substance that is 

 the cause of the phenomena of pro-cestrum and oestrus. There 

 is practically no loss of follicular cells upon rupture, and they 

 become transformed into luteal cells. Rupture is brought about 

 by the formation of a secondary liquor folliculi which is produced 

 subsequent to successful insemination. 



Other papers include : Camp, " Excavations of Burrows of 

 the Rodent Aplodentia, with Observations on the Habits of 

 the Animal " {Univ. Col. Pub. Zool. May 191 8) ; Taylor, " Re- 

 vision of the Rodent Genus Aplodentia " (ibid. June 191 8) ; 

 Sugita, " Comparative Studies on the Growth of the Cerebral 

 Cortex. Parts 5, 6, 7, 8 " (Jour. Comp. Neur. vol. xxix. 

 April and June 191 8) ; Stockard and Papanicolaou, " Further 

 Studies on the Modification of the Germ-Cells in Mammals ; 

 The Effect of Alcohol on Treated Guinea-Pigs and their 

 Descendants " (Jour. Exp. Zool. vol. xxvi. May 191 8) ; Papani- 

 colaou and Stockard, " The Development of the Idiosome in 

 the Male Germ-Cells of the Guinea-Pig " (Amer. Jour. Anat. 

 vol. xxiv. May 191 8) ; Hatai, " On the Weight of the Epidi- 

 dymis, Pancreas, Stomach, and of the Submaxillary Glands 

 of the Albino Rat (Mus norvegicus albinus) according to Body 

 Weight " (ibid.) ; Meyer, " The Absence of Hemal Nodes in 

 the Domestic Pig," and " Some Observations on Megacytes in 

 Lymphatic Tissues " (both ibid.) ; Hays, " The Influence of 

 Excessive Sexual Activity of Male Rabbits on the Nature of 

 their Offspring " (Jour. Exp. Zool. vol. xxv. April 191 8) ; 

 Lloyd- Jones, Orren, and Hays, " The Influence of Excessive 

 Sexual Activity of Male Rabbits. I. On the Nature of the 

 Seminal Discharge " (ibid.) ; Stewart, " Changes in the Relative 

 Weights of the Various Parts, Systems, and Organs of Young 

 Albino Rats Underfed for Various Periods " (ibid.) ; Hatai, 

 " On Several Effects of Feeding Small Quantities of Sudan III 

 to Young Albino Rats " (ibid. May) ; King, " Studies on In- 

 breeding. I. The Effects of Inbreeding on the Growth and 

 Variability in the Body Weight of the Albino Rat " (ibid.) ; 

 Whiting and King, " Ruby-eyed Dilute Grey, a Third Allelo- 



