14 
CORN. 
brown flat chrysalis, in size and shape and colour strongly resembling 
a rather small and narrow flax-seed, whence the name of “ flax-seeds ” 
Attacked Barley-stems. 1, elbowed down ; 2, showing “flax-seeds.” 
E 0 
is commonly given to these chrysalis-cases or puparia. Within this 
hard outer husk the maggot changes to chrysalis, and the chrysalis to 
the perfect fly, but how long this may take depends very much on 
circumstances. It may occur, under natural 
and favourable circumstances, so soon that the 
whole time occupied in the life of the fly from 
egg to development is only forty-eight days ; but 
it has been shown that if the puparium —to give 
it the precise name—is put in unfavourable 
circumstances, development may be greatly 
“Flax-seeds” or puparia retarded. Thus some of the flies may come 
in different stages of de- ou t j n autumn in the fields, and others threshed 
velopment,nat. size and ....... . . . „ 
mag. out, or stacked m the straw, or kept artificially 
for investigation, may very likely not hatch until 
May, or much later in the following year. The perfect fly much 
resembles a stout-made little brown gnat, about one-eighth of an inch 
in length, with one pair of smoky-grey wings, and with long horns. 
For those who desire a full and trustworthy scientific description 
of the fly (that is, the imago of Cecidomyia destructor , Say) I append 
the technical account of both male and female by Mr. R. H. Meade, 
