1897.] 



OF THE LEGS IN THE BLATTID.?). 



905 



Brunner ^ quotes Serville's remarks, and states that he could 

 add a large number of cases. He observes that the abnormal 

 tarsus is usually unilateral and on the posterior legs {Nyctibora, 

 Epilanijjra, &c.). 



The above-mentioned authors examined only small numbers of 

 individuals, and it was therefore desirable to extend the inquiry 

 as to the frequency of occurrence of abnormal tarsi through greater 

 numbers. This has been done among certain easily obtained 

 species, the total numbers examined being : — 



The specimens of P. americana and F. germatiica were obtained 

 from the Society's Gardens, those of P. australasue from the Botanic 

 Garden, Cambridge (wbere the egg-cases of this species appear to 

 have been introduced in packets of plants from Kew and South 

 America), and those of S. orientalis from Cambridge bakehouses, 

 except 262 captured in a bakehouse at Poole, Dorset. The speci- 

 mens of P. americana and P. germanica were caught by hand, and 

 those of the other two species by traps. This probably explains 

 the small number obtained of the young of the two former species, 

 as the larger adults are more easily picked up. 



It is possible that some of the young of P. germanica were 

 wrongly included as belonging to P. americana, for both species 

 occur in the same warm houses in the Society's Gardens. 



An examination of these specimens showed the percentage 

 frequency of occurrence of individuals with one or more tarsi 

 four-jointed to be as follows :■ — 



Table B. 



' Nouv. Syst. des Blattaires, p. 146. 



Peoc, Zool. Soc— 1897, No. LX. 



60 



