354 MR. E. DEGEN ON ECDYSIS. 



'J'hus, the comparatively slight discrepancies uliich must necessarily accrue from the 

 adoption of the theoretical, yet more serviceable, equivalents to those of the empirical 

 figures of their actual measurements, can exert no serious influence on the general 

 result of this investigation. 



IV.— EXPLANATORT REMARKS ON THE DIAGRAMS ON PlaTES, TaBLES, AND ClIARTS. 



From the 27 specimens more generally described, it seemed advisable to make 

 a narrower selection of 12 typical cases for the purpose of diagrammatic reproductions 

 which illustrate the relative stages of that particular phase which each remex pursues 

 during the moult. 



In the diagrams allotted to them in Plates XXXVI.-XXXVIII., these specimens 

 have received a special mark in the shape of a Roman capital letter, irrespective of 

 their serial numbers, which latter are those associated with the dates on which they 

 were received. With these tlie capital letters correspond tolerably well for denoting 

 the successive stages which are marked by a small Latin letter. The reason for 

 this is that some birds commence to moult sooner than others, and in consequence 

 accomplish the moult earlier. For instance, specimen No. 16, marked F (see 

 Plate XXXVII. ), of Dec. 19, Avhich repeats stage (/, precedes No. 14, of Dec. 11, which 

 is marked G (Plate XXXVII.), because this latter specimen has attained the stage of h, 

 which represents the growth of remex VIII. at an earlier date. A similar case to the 

 one mentioned is that of No. 24, and further marked M, of Feb. 18 (Plate XXXVIII. ), 

 which had to be placed at the end for representing stage V, or the development 

 of cubital v., as the last remex to appear, because it is a more typical specimen iu 

 this respect than No. 25, in which the moult of the same quill has been seemingly 

 accomplished though not entered. Otherwise it bears the same date as the latter 

 specimen — a circumstance which is purely accidental, on account of their having been 

 shot together. Both of these, therefore, antedate No. 26, marked L (Plate XXXVIIL), 

 this having been procured on March 4, which represents the stages intermediate between 

 i and k, which are earlier than that of No. 24, as we have seen. 



Many of these specimens being more or less a repetition only of those extracted for 

 diagrammatical representation, or calling for no special remarks, are referred to only 

 in a general way. Their quotients for the relative lengths of remiges in moult are, 

 however, entered, together with those specially selected for illustration, separately in 

 the two parts of Table I. : part a for the left and part b for the right wing (see 

 pp. 356-859). 



The capital letters which the specimens received in Table I., parts a and h, corre- 

 spond with those of the diagrams in Plates XXXVI.-XXXVIII. The specimens are 

 arranged in Table I. in the order of the dates on which they were received. Tlie 

 Roman figures placed at the head of the columns specify the order of the remiges for 



