^O PSYCHE [October 



meat of the nut which, as a rule, it will have wholly consumed by the time it is 

 grown (Plate VI, fig. 2) . When the nut falls the larva leaves it, buries itself in the 

 earth at considerable depth, which is probably to avoid freezing. Ordinarily but 

 one larva lives in a nut, though two and even three are sometimes found. Since 

 in this case they are invariably smaller there is an evident lack of nourishment. 



The adults appear above ground any time after the first of June, some even 

 as late as July or August. 



My material, which abundantly represented all stages of metamorphosis, was 

 obtained by collecting a large quantity of acorns of the white oak {Qiurcus alba) 

 when they fell in autumn, and placing them on a box filled with earth and grass 

 sod. In a very little while the larvae bored out, entered the earth and buried them- 

 selves near the bottom of the box. This was kept in the Laboratory where the 

 normal temperature was about 21° C. and probably never lower than 18° C. 



Specimens were taken out at weekly intervals and fixed. Through the winter 

 there were no signs of metamorphosis. This suddenly took place in the spring. 



The first imago was seen April 9th, and within the next two weeks they were 

 abundantly found. April 23 the remaining specimens which represented all stages 

 of development were taken out and fixed. This does not agree with Miss Murt- 

 feldt's results, but if left undisturbed they might possibly not have emerged until 

 much later.^ 



Balaninus nasicus Say (Plate VI, fig. i), representing the extreme development 

 of the Rhyncophorous rostrum, and, being the species I had under observation and 

 control, has been the chief subject of study for the following paper. The account 

 of the larva in particular is drawn wholly from Balanitius while Monouychus has 

 served best for the study of internal metamorphic processes. 



Methods — For fixation 70 % alcohol, first heated to boiling, was used with 

 excellent results ; paracarmine was used for staining in toto with a counterstain 

 of orange or methyl blue on the slide ; haematoxylin was mainly used for staining 

 sections followed by eosin or picro-fuchsin as counterstain ; whole preparations 

 were stained with borax-carmine and diliferentiated with acidulated alcohol. 



The development of the rostrum will be best understood by studying the parts 

 concerned, firstly, in the larva, which has no rostrum ; secondly, in the adult, which 

 has it complete ; and thirdly in transforming larvae and pupae, which show every 

 phase of its growth. 



' Excellent accounts of the habits of Balaninus liave been published by Dr. John Hamilton in Can. Ent., Vol. 22, pp. 

 1-8, 1890, and Miss Mary E. Murtfeldt in Itisect Life, Vol. VI, p. 318, 1894. 



