FLUCTUATING VARIATIONS AND THEIR INHERITANCE 47 



Specifically, the variations by addition consist of : 

 (a) the presence of spurs in unexpected places; such as two short 

 cephalic spurs between the forkings of R^ and Rg^^ in a right wing 

 (specimen Sub. 4. H) ; two longer spurs or short branches running 

 from R3 near its distal end to the wing's costal margin in i right wing 

 (specimen Sub. i, O) ; a spur running proximad from R, shortly beyond 

 its forking in i left wing (specimen Sub. 4, L) ; a spur originating 

 from the middle of R^ and running proximad in i right wing (specimen 

 Sub. 2, I) ; a spur originating from the 2nd anal vein and directed 

 toward the inner margin in i left wing (specimen Sub. 3, C) ; 



Fig. I. Venation of the silk-worm moth, Bombyx mori. 



(b) very short additional cross-veins, as where there is a cross- 

 vein connecting R3 with R^ near their distal tips in i left wing (speci- 

 men Sub. I, C) ; or a short cross-vein running cephalad from R^ to the 

 costal margin in i right wing (specimen Sub. 2, I). 



2. Variation by loss of certain veins entirely or in part. 



The variations are numerous and striking in kind and are repre- 

 sented by many variants. The veins involved include members of the 

 radial, medial and anal series in the fore-wings and the medial, cubital 

 and anal series in the hind-wings. 



The variation in the radial series consists of a "continuous" varia- 

 tion on the part of Rg. This summary included 46 left and 43 right 



