260 Variation in the Mealworm, Tenebrio molitor 



No. 38. An increase of the number of tarsal elements may occur, 

 either only in the third pair of legs, either in one leg or in both legs ; 

 the tarsus then consists of five segments ; 



No. 39. Or only in the second pair of legs; the tarsus is then 

 built up of six segments ; 



No. 40. Or in the second and third pair of legs (the first pair 

 being normal) ; 



No. 41. Or in all legs. Fig. 16 al 



a3 



Fig. 16. 



a^, six legs of beetle having a supernumerary joint in each tarsus, d and di, tarsi 

 imperfectly divided, p, reduplication of apical joint. 



The increase is only one joint above the normal, so that the above- 

 mentioned cases showed the following number of tarsal segments. 



No. 38 

 No. 39 

 No. 40 

 No. 41 



First pair 

 of legs 



5 



5 



5 

 6 



Second pair 

 of legs 



5 



6 

 6 

 6 



Third pair 

 of legs 



5 

 4 



6 

 5 



In consequence of the positive results obtained with respect to the 

 heredity of a reduced number of tarsal segments I have paid much 

 attention to the above-mentioned cases of an increased number of joints, 



