SECT. 2] 



AND WEIGHT 



539 



into the air-space of chick eggs on the 5th day of development. The 

 effect was absolutely nil, as is seen from Figs, 87 & 88 where his points 

 are plotted both for wet and dry weight. There is thus a certain con- 

 tradiction between the results of Willier and those of Hanan ; Okada 

 afterwards repeated Hanan's experiment, and observed no effect on 

 the general appearance, but an 18 % decrease in length and weight 



of the chicks from the injected eggs. There were characteristic histo- 

 logical changes, mostly in the direction of precocity. Okada's results 

 would fit in with Butler's finding of a decrease in cell-division rate 

 under the influence of thyroxin in Arbacia eggs. 



Pituitrin has also been injected into hen's eggs, by Cunningham 

 & Stanfield, who obtained the following results : 



Average weights (gm.) 



Injection 7th day, opened gth 

 Injection 7th day, allowed to hatch 

 Injection 6th day, opened 8th 



