288 



(1904, 1. c. p. 423): „The moment of the hatching does not cor- 

 respond to an exact point of the embryonic evolution. This mo- 

 ment is of a purely physical nature and depeuds on the smaller 

 or larger quantity of nutritive reserves contained within the egg'\ 

 we may expect that in other families segment 12a will remain 

 independent till after the first instar. The more so as in 1896 

 Chapman was able to show so great a difference between the 

 eggs of Lepidoptera. 



Therefore we need not be surprised if some writers are con- 

 vinced that there are more than ten abdominal segments, and others 

 that there are only ten or less. 



For my part I think that it entirely depends on the specimens 

 examined. 



PouLTON (1890) says that „behind the 7tli abdominal segment 

 most writers only detect a somewhat confused mass of segments, 

 but a carefnl comparison with the pupa proves that it is certainly 

 made up of three segments." He arrived at this conclusion through 

 the homologizing of the setae and through Jackson's investi- 

 gations (in 1890) on the pupae, which harmonized with the older 

 (1875) observations of that writer on the so-called cremaster of 

 the pupae, proving it to be the samo as the anal-flap of the 

 caterpillars. Poulton's conclusion is 1. c. p. 195: „In the pupa, 

 this ninth abdominal segment, although small, is as distinct as 

 any of the others. The part behind this segment in the larva 

 forms a tenth abdominal segment. This segment is separated into 

 a dorsal portion (X') of which the posterior and lower part form 

 the anal-flap and a ventral portion (X), of which the anal claspers 

 form the posterior and lower part, between the latter is the anus". 

 On p. 196 he says that for a long time he has considered that 

 X consisted of two segments. 



Spuler (1910) also believes he can discern a 14th segment, 

 fig. 4, p. XXVII. The last three segments he takes together as the 

 anal segments. They often bear an „After-klappe". „That the last 

 part should be looked upon as the dorsal part of a 14th ring, 

 consequently of the llth abdominal segment, is proved by the 



