Bramble-bees and Others 



according to the diameter of the shell. They 

 are bounded back and front by partitions of 

 pure resin, without any encrustations of mi- 

 neral particles. Their number is exceedingly 

 restricted and is usually limited to two. The 

 front room, which is larger because the width 

 of the passage goes on increasing, is the abode 

 of a male, superior in size to the other sex; 

 the less spacious back room contains a female. 

 I have already drawn attention, in an earlier 

 chapter, to the wonderful problem submitted 

 for our consideration by this breaking-up of 

 the laying into couples and this alternation of 

 the males and females. Without calling for 

 other work than the transverse partitions, the 

 broadening stairway of the Snail-shell thus 

 furnishes both sexes with house-room suited 

 to their size. 



The second Resin-bee that inhabits shells, 

 Anthidhim belUcosum, hatches in July and 

 works during the fierce heat of August. Her 

 architecture differs in no wise from that of 

 her kinswoman of the springtime, so much so 

 that, when we find a tenanted Snail-shell in 

 a hole in the wall or under the stones, it is 

 Impossible to decide to which of the two spe- 

 cies the nest belongs. The only way to ob- 



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