664 EXPERIMENT STATION RECORD. [Vol 40 



Degenerating corpora lutea produced at the preceding ovulations are also 

 present. These consist mainly of dense connective tissue, but occasionally 

 they can not be distinguished from the recent ones by the naked eye. All the 

 corpora lutea of the same pregnancy In both ovaries are alike in cytological 

 structure. 



The corpus luteum was found not to be the simple parenchyma of lutein cells, 

 supported by a framework of connective tissue, figured in the manuals, for 

 other types of cells were present, particularly toward the end of pregnancy. 

 One Is thought to be the " theca lutein cells " of other observers. The author 

 is inclined to believe that the true lutein cells are developed entirely from 

 the granulosa and not from the theca interna. In the early stages lutein cells 

 show a canalicular apparatus in the outer protoplasm. 



The corpus luteum of pregnancy is distinguished from that of ovulation by 

 a more regular and uniform appearance and a lesser infiltration of fat. Dur- 

 ing pregnancy the Graafian follicles do not undergo the process of ripening and 

 change in the theca interna that is preparatory to rupture. 



In a series of 117 uteri there were 28 cases in which one horn contained an 

 embryo more than the number of corpora lutea in the corresponding ovary, 

 13 in which a horn contained 2 more, and 2 in which the excess was 3. It is 

 concluded from these facts that extra-uterine migration of the ovum is a nor- 

 mal and frequent occurrence in swine. 



Studies on the physiology of reproduction in birds. — VIII, The effects of 

 quinin on the production of egg yolk and egg albumin, O. Kiodi.k and C. E. 

 Anderson (Amer. Jour. Physiol., J,l (1918). No. 1, pp. 9&-102). Eleven female 

 ringdoves, both the blond and white varieties (fitoreptepeMfl risoria and S. 

 alba) and erossbreds, were given daily doses of from 0.26 to 0.5 grain 

 of quinin sulphate for periods varying from three to ten weeks. The eggs and 

 their included yolks during the feeding period weighed less than those pro- 

 duced before or afterwards. A lessened secretion of albumin is indicated, as 

 the decrease in weight of yolk was not sufficient to account for all of the 

 decrease in weight of the egg. After cessation of quinin feeding the yolk 

 recovered its normal weight very slowly, while the weight of the albumin rose 

 quickly, and even for a short time seemed to be abore normal. 



Twelve yolks from the quinin period were burned in a bomb calorimeter 

 and the energy per gram of moist weight was found to be the same as in 

 eggs laid under normal conditions, whence it is concluded that the ratio of 

 lipoids to proteins in the yolk is unchanged by the quinin feeding. The author 

 believes that quinin restricts protein metabolism, and interprets his results on 

 this basis. 



The earlier numbers of this series of papers have already been noted (E. S. R, 

 37. p. 772). 



Sex studies. — X, The corpus luteum in the ovary of the domestic fowl, 

 R. Peakl and A. M. Boring (Amer. Jour. Aunt.. 28 (1918). So. 1. pp. 1-18. pis. 

 9, fif/s. 6). — Continuing the series previously noted (E. S. R., 39, p. 177). a 

 histological study was made of the ovaries of several domestic fowls and of a 

 guinea hen. Preparations of cow ovaries were used for comparison. 



In the bird ovaries certain cells of the theca Interna Of any follicle that bad 

 discharged its ovum or had become atretic while retaining an ovum were found 

 to take on the appearance and chemical reactions of the lutear cells of late 

 involution stages of the corpus luteum of the cow. These cells eventually fill 

 up the cavity of the follicle. They contain a yellow fatty substance that 

 stains readily with Sudan III, and in addition develop characteristic yellow 

 granules which, judging from their reaction to histological reagents, are neither 

 fats nor proteins. 



