1899] REGENERATION IN ORTHOPTERA 321 



perfect ; but iu the second case an unjointed stump is formed. There 

 seems to be no appendage which may not suffer mutilation during the 

 hazardous process of moulting. 



In jumping Orthoptera, tarsal regeneration occurs readily on any 

 of the legs, and this conforms with the fact that mutilation of the 

 tarsus is peculiarly liable to occur during moulting. Experiment 

 shows that the terminal portion of the tibia may also be regenerated, 

 and this too may be associated with the fact that in exuvial mutilation 

 or, more rarely, as the result of attack, the muscles at the end of the 

 tibia are often torn when the tarsus is pulled off. 



Bordage also notes that in Phylloptera laurifolia and Conoc&phalus 

 differens the regenerated tarsus is tetrameral, as is normal in Locustidae, 

 while in Crryllus campcstris the regenerated tarsus has three joints. 

 In Locustidae and Gryllidae the tibia of regenerated anterior legs does 

 not possess the tympanic apparatus borne on the normal limb. 



Diastataxy. 



The Journal of the Linncan Society — Zoology — for July, vol. xxvii., 

 contains two very important contributions towards a solution of that 

 ornithological puzzle known hitherto as " Aquinto-cubitalism." Mr. P. 

 Chalmers Mitchell has approached the question from the point of view 

 of comparative anatomy ; Mr. W. P. Pycraft from that of embryology. 



The riddle to be solved, it will be remembered, was the meanino- of 

 the constant absence of a remex from between the fifth pair of secondary 

 major coverts of the wing in certain birds, or groups of birds. Wings 

 in which this feather was wanting were known as aquinto-cubital ; 

 when there was no such deficiency the wing was known as " quinto- 

 cubital." 



Mr. Mitchell has proposed the term diastataxic for the former, and 

 eutaxic for the latter. These terms are undoubtedly superior to the 

 older ones, and have been adopted by Mr. Pycraft in his paper. 



Till now, it was believed that in the diastataxic wing the fifth 

 remex was missing ; both the present authors agree, however, that this 

 is not the case. 



Mr. Pycraft endeavours to show that the remex in question has lost 

 its original relations, but not its existence. According to him the 

 diastataxial wing is at first eutaxic, changing more or less suddenly during 

 development from the one into the other. This is brought about by a 

 remarkable, but unmistakable shifting of position of all the coverts of 

 the dorsal surface of the wing and of the remiges (1-4). The remiges 

 in question move outwards (wrist- wards), and backwards, the movement 

 being accompanied by certain of the obliquely transverse row of 

 coverts (1-5). As a consequence, the fifth of these rows becomes 



