451 



SUMMAEY OF CUKRENT EESEAECHES 



EELATING TO 



ZOOLOGY AND BOTANY 



(principally invertebrata and cryptogamia), 



MICBOSCOPY, Etc.* 



ZOOLOGY. 



VERTEBRATA. 



a. Emtoryolog'y.t 



Process of Ovulation.^ — S. S. Schochet has studied this in the sow. 

 It is generally concluded that pressure atrophy of the ovarian stroma 

 is the chief means by which the extrusion of the ovum becomes possible. 

 During the growth and maturation of the ovum, the cells of the Graafian 

 follicle, after increasing greatly in number, begin to disintegrate and 

 liquefy. From then onward, due it is thought to the different chemical 

 composition of the fluid or of the general content of the folUcle, an 

 endosmosis seems to be induced which increases the liquor folliculi to 

 an amount far greater than can oe regarded as consequent on the lique- 

 faction of the follicular cells. The follicle distends and, following the 

 direction of least resistance, forms a l)ulging on the surface of the ovary, 

 dispersing the ovarian stroma, thinning its tunica albuginea and the 

 overlying epitheHum, and results in a compression of the blood capillaries 

 intervening between it and the surface of the ovary. Clark has shown 

 that the capillaries in the summit of the bulging are practically obliterated 

 by the pressure. It is supposed that nourishment is thus cut off from 

 the ovarian stroma under compression, and that the stroma atrophies 

 till its resistance is less than the pressure exerted by the distending 

 follicle. The content of the follicle then bursts into the body cavity. 

 The liquefying of the follicular cells having continued till the ovum is 

 free within the follicle, the ovum is extruded into the body cavity with 



* The Society are not intended to be denoted by the editorial" we," and they 

 do not hold themselves responsible for the views of the authors of the papers 

 noted, nor for any claim to novelty or otherwise made by them. The object 'of 

 this part of the Journal is to present a summary of the papers as actually -pub- 

 lished, and to describe and illustrate Instruments, Apparatus, etc., which are 

 either new or have not been previously described in this country. 



t This section includes not only papers relating to Embryology properly so 

 called, but also those dealing with Evolution, Development, Reproduction, and 

 allied subjects. 



X Anat. Record, x. (1916) pp. 447-57. 



