936 



MB. H. H. BBINBLET ON EEPEODUCED 



[Dec. 13, 



Table C. — Stylopyga orientalis. 

 5-jointed. 4-jointed. 



The definitely constituted nature of the 4-jointed form of 

 tarsus in both young and adult individuals and on all three pairs 

 of legs is illustrated by Table C, and from the values recorded 

 therein it is obvious that the behaviour of the 4-jointed form is in 

 general agreement v\'ith that of the normal tarsus. If the relative 

 A alues of the several joints iu the latter are examined, it is seen 

 that the total length is rather more evenly distributed among 

 the joints in the case of Pair I. than in that of Pair II., and iii the 

 case of Pair II. than in that of Pair III. This is most easily seen 

 in the case of the longer joints, j^ and j^, though the shorter 

 intermediate joints are also concerned. In any single individual 

 animal the total length of the tarsus is of course greater in Pair 

 III. than in Pair II., and in Pair II. than in Pair I. So that in a 

 longer (more posterior) tarsus j^ is relatively greater and j. rela- 

 tively smaller than in a shorter (more anterior) tarsus. Now in the 

 case of the 4-jointed tarsi it will be seen that Jj and J^ are affected 

 in a similar manner. Again, the values for the 5-jointed tarsi 

 present a strong indication that 7, is relatively longer in adult than 

 in immature individuals, j^ being affected inversely. So is it for 

 Jj and J^ respectively in the 4-jointed tarsi. The measurements 

 formiug the data for constructing Table C were purposely taken 

 fi'om young of all' sizes, from newly hatched to over 20 cm. in 

 body-length (penultimate instar) ; and a consideration of the 

 cases in order of age did not reveal any reliable indication that the 

 above noted alteration in the ratios of j^ and ./. was established 

 progressively. The relative increase of ;/j and decrease of /, appear 

 to be coincideut with the attainment of maturity, and the same 

 is true for J, and J^. It is admitted that the above statements 

 are based on a comparatively small total of observations, and that 



