MISCELLANEOUS 59 



blotches, etc. In no case has one of these sports yet shown any 

 potency in heredity. 



Melanic moths, not black, but with wings and body strongly smoky 

 not infrequently appear (PI. II, fig. 4). In various lots in various 

 races these melanic or "darky" moths have been noted. And much 

 work has been done in testing the inheritance behavior of this melan- 

 ism. The general result is like that for all the other sporting charac- 

 ters (except the moricaud larval pattern) so far noted and studied, 

 namely, it has no potency in heredity and does not behave as an alterna- 

 tive or Mendelian character. It shows a certain tendency in pure 

 matings (that is smoky male mated with smoky female) to reproduce 

 itself and careful selection could in time probably produce broods in 

 which melanism would be the rule. The occurrence of melanic indi- 

 viduals is much more abundant among males than among females. No 

 special evidence has yet been adduced to show that this melanism is 

 not congenital, but is caused by special conditions surrounding the 

 ontogency. As all the individuals of any one lot of silkworms (by 

 lot being meant all the worms derived from the eggs laid by a single 

 female) are reared under as nearly identical conditions as possible, the 

 occurrence of two or four or a dozen melanic moths in such a lot of two 

 or three hundred individuals is evidence for the distinctly congenital 

 nature of the variation. However, in some experiments which included 

 the rearing of silkworms in an atmosphere of high humidity maintained 

 during the whole larval life, the moths produced by these larvae prac- 

 tically all showed a marked melanic tendency, although the character 

 of the smoky coloration was somewhat different from that which often 

 appears as a sport and which has given in my laboratory the name 

 "darky" moths to the individuals showing the variation. 



The studies into the nature and character of behavior in inheritance 

 of this sporting melanism are being continued. (Eighteen matings were 

 made on this basis in 1906 and most of the lots reared through to 

 maturity in 1907, and a new set of matings made for the 1908 rearing 

 season. The rearings made in earlier years from matings made on a 

 basis of this character were unfortunately not well followed up). 



Flying moths and moths with rudimentary wings. The occasional 

 appearance of male moths exhibiting a considerable power of flight 

 (the silkworm moth although retaining its wings, probably in full size, 

 has lost the power of flight, its wing-vibrations being no longer strong 

 enough to carry its body), and the rarer appearance of moths with 

 greatly reduced or rudimentary wings led to a number of matings to 



