294 SUMMARY OF CURRENT RESEARCHES RELATING TO 



fatty substance, as shown by the Sudan Til, absolute alcohol and xylol 

 reactions. In both there develops in the cells a yellow amorphous- 

 pigment containing the fatty substance. In the hen a corpus luteum 

 forms in both discharged and atretic follicles. Its origin is definitely 

 from the theca interna. J. A. T. 



Chondriosomes in Testis-cells of Fundulus.— G. Duesberg {Amer. 

 Journ. Anat., 1918, 23, 133-53, 2 pis.) has traced the behaviour of 

 very distinct chondriosomes in the testis-cells of this Teleost. It is very 

 probable that, owing to their close contact with the nucleus, they are 

 carried into the egg at the time of fertilization. , J. A. T. 



Growth of Mice. — Helen B. Thompson and Lafayette B. 

 Mendel {Amer. Journ. Physiol., 1918, 45, pp. 431-60, 10 figs.) find 

 that up to the twenty-sixth day of life in the albino mouse the actual 

 gain per day is approximately the same for the two sexes. After the 

 twenty-sixth day the males continue to grow with comparative rapidity 

 until about the fortieth day, whereupon the slower, gradually diminish- 

 ing rate of increment ensues. The females gain from the twenty-sixth 

 day at the rate of 0*5 grm. per day until the thirty-fourth day, when 

 their curve flattens perceptibly. The resumption of growth after sup- 

 pression of growth is followed by a greatly accelerated rate. The 

 acceleration is ordinarily accomplished on a smaller intake of food than 

 is ingested during a period of equal growth at the normal rate from 

 the same initial body-weight. J. A. T 



Growth of Blood-vessels in Frog Larvae. — Eliot R. Clark 

 {Amer. Journ. Anat., 1918, 23, 37-88, 16 figs.) finds that an 

 extensive vascular development takes place in early embryonic stages 

 which is independent of the mechanical factors concerned with the 

 circulation of the blood and the interchange of substances through the 

 endothelial wall. The extension of the blood-vascular system takes 

 place by sprouting and by the formation of anastomoses between sprouts, 

 and the early steps are due to hereditary inertia. This stage, however, 

 comes to an end relatively early ; and the vascular system, for its 

 further development into the complicated and nicely balanced system of 

 the adult animal, comes to be dependent upon the mechanical factors 

 concerned with the pull and push of outside tissues, with blood-pressure 

 and blood-circulation, and with the interchange of substances through 

 the wall. " J. A. T. 



Inheritance of Coat-colour in Cats. — P. W, Whiting {Journ. 

 Exper. Zool., 1918, 25, 539-09, 2 pis.) has made an experimental 

 study. Maltese dilution segregates distinctly from intense colour, and 

 is probably recessive. Solid white is a simple and complete dominant 

 over colours. White spotting is very irregular in inheritance. There 

 is a partial correlation between dominant white, blue eyes, and deafness. 

 Yellow is determined by a sex-linked factorial difference from other 

 colours. Kittens resembling adult Siamese cats have been produced 

 from common cats. Banding cleanly segregates in three different widths. 

 Miich-ticking, little-ticking, and black probably constitute a triple allele- 



