35^ Raymond Pearl 



addition to the logarithmic approach of successively formed 

 structures to a type ("first law of growth") there was also a reduc- 

 tion of variability with successive whorl formation ("second law 

 of growth"). Of such a reduction of variability with continued 

 formative activity we find no evidence in the case described in this 

 paper. If such a law obtained in this case it would be expected 

 that the zigzag line in plate II would exhibit progressively smaller 

 and smaller fluctuations up and down about the smooth curve 

 the farther out on that curve one went. The diagram shows that 

 this is not the case. The fluctuations are just as frequent and 

 extensive at the end of the curve as at the beginning. The only 

 difference is that they are about a difi^erent mid-point in the upper 

 part of the curve from what they are at the start. 



SUMMARY 



1 The plan of a comprehensive investigation of the problem 

 of the physiology of reproduction in the domestic fowl is set forth 

 in outline, and a statement is made of the general standpoint from 

 which the problem is being attacked (pp. 339 — 342.) 



2 A description is given of a case in which the first egg laid 

 by a certain pullet was very abnormal in shape. There was a pro- 

 gressive change in the successive eggs laid by this pullet. This 

 change was of a regulatory character, the eggs finally coming to 

 be normal in shape. 



3 It is shown that this progressive regulatory change follows 

 a logarithmic curve, and the significance of this fact is discussed. 



4 The data obtained in this case are held to warrant the con- 

 clusion that the shape of the egg is determined by the muscular 

 activity of the walls of the uterus, j 



