4 (1 96) INTRODUCTION. 
breadthof the skull of some races of caviae in three successive gener- - 
ations. As for the index, he does not mention it. CASTLE finds that in Fy 
length and breadth agree with the greatest length and the greatest 
breadth of both P-forms. F, shows an intermediate varıability. Of one 
of the specimens of F, the length of the skull (also of the upperbone) 
agrees in one of the crosses with the smallest value of the P-forms. A 
conformable small value of the breadth has not been found in the ma- 
terial. A specimen with a very long skull (and a long femur), longer 
than the longest specimen of the longest of the P-forms was also found; 
in this case, too, among the data a conformable very great breadth is 
lacking. It may be that the investigation into the heredity of the index 
would have given the explanation of these facts. In his results CASTLE 
especially sees the expression of the luxuriousness of bastards. 
About the non-hereditary variability and the modificability of head- 
form I formeıly made some remarks (1919, p. 351). 
At the beginning of a Mendelian inquiry we have also to consider 
whether the property that is to be investigated is appropriate for 
such an inquiry (1919, p. 355; 1920, p..119), 1. e. whether it is inde- 
pendent. In this respect the headform surely offers some difficulties. 
About the experience with his material of beans in which he also dis- 
tinguishes brachysperme and dolichosperme races, JOHANNSEN (1907, « 
DT 
p. 187) writes: ” jedenfalls möchte ich aber betonen, dass es mir richti- 
ger und einfacher erscheint, in erster Linie die absoluten Messungen, 
Längen, Breiten und andere Dimensionen anzugeben und zu bearbei- 
ten. Wohl stehen alle solche Grössen in Korrelation im gegebenen Or- 
ganismus, aber bei den Messungen sind nicht direkt Korrektionen aus- 
zuführen und die absoluten Messungen bilden ja doch die fundamenta- 
len Fakta, auf welche die Forschung sich stützen soll.” 
We have investigated the heredity of the length and of the breadth, 
(1920a) as well as that of the index and wish to remark already here 
that it is very likely that, if the characteristics length, and breadth are 
bound in the headform, these dimensions, although "fundamentale 
Fakta,’ because they are directly measurable are not independent and 
consequently are less appropriate for Mendelian investigation (1919, 
p. 355). TSCHEPOURKOWSKY, too, expresses himself in this way (1905, 
p. 292): "We must therefore conclude that the diameters of the head 
and the cephalic index respectively depend on many causes. The 
anthropometric measurements are often artificial simplifications made 
I“ PNT 
RE 
