( XXV ) 



Of the bucephala submerge J, 24 emerged after 1, 2, 3, 4, 5, 6, 

 7, JO, 11 and 12 days respectively, many more afterwards ; of 

 the unsubmerged 8 emerged. Of the falcatar ia and curoalula 

 at least 66 emerged after 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 

 13, 14, 15, 16, 17, 18, 19 and 20 days (10 of the pupae sub- 

 merged had first slipped out of their cocoons, and 8 of those 

 emerged) ; of those unsubmerged about the same proportion 

 emerged ; of the limacodes, nearly all emerged ; of the sub- 

 merged levana only 3 emerged, after 1, 3 and 9 days 

 respectively. 



"Of the submerged bilunaria not one emerged, but of the 

 20 unsubmerged 13 emerged. That result was so surprising 

 as compared with the other submerged pupse that I thought 

 the fatal consequences might have been owing to the fact that 

 the 18 pupae had been deprived of the protection of their 

 cocoons (though this had not affected the falcataria). There- 

 fore in the winter of 1904-5 I tried the experiment with 

 this species on a large scale. Of 50 submerged in their 

 cocoons and taken out in lots of about 4 for 12 successive 

 days nearly all emerged, very few being cripples, but of 23 

 submerged naked and taken out in from 1 to 5 days, only 2 

 emerged, both cripples. Of 34 other naked pupa) not sub- 

 merged the great majority have emerged, about a quarter 

 of them cripples, while of 50 left in their cocoons, but 

 unsubmerged, nearly all have emerged, very few of them 

 being cripples. 



" The inference to be drawn from these experiments appears 

 to be that in the case of subterranean naked pupa) sub- 

 mergence for 20 days is not injurious. Of moth pupee that are 

 not subterranean, such as falcataria, limacodes and bilunaria, 

 submergence for 12 days or more is not injurious, with the 

 proviso that if bilunaria is without its cocoon it will almost 

 always be killed even if the submergence is only for a day. 

 As to levana the pupa) were probably unhealthy, as shown by 

 the large number of the unsubmerged that died ; the numbers 

 of both that survived are too few for any decided inference, 

 but it is established that this naked pupa can survive 

 submergence for 9 days. 



" The power of resistance of pupa) to submergence seems 



