THE CANADIAN ENTOMOLOGIST. 99 



deprecated. I think entomologists might be more generous to one 

 another. For my own part I would gladly pay handsomely in specimens 

 to anyone who would name for me what I send, but I do not like parting 

 with unique specimens. I collect only Manitoba insects, and have 

 several species of which I have only seen single examples during the 

 seventeen years I have been in the country. I have them annexed by 

 some specialist. What then? I might, having taken the species, replace 

 it by specimens from Nevada or Colorado, let us say. But they would 

 not be Manitoban specimens, and very likely would present certain minor 

 differences. All thanks and credit being given to those who, through 

 greater advantages and opportunities, have acquired a knowledge which 

 it is impossible for many of their brethren who are less favourably 

 situated to gain, and impart that knowledge, but they exact too heavy a 

 price for it, and by so doing, instead of encouraging the study of ento- 

 mology, confine it within narrow limits by their action. 



E. FiRMSTONE Heath, Cartwright, Manitoba. 



TRYPETA SOLIDAGINIS. 



BY MRS. A. J. SNYDER, BELVIDERE, ILLINOIS. 



A year ago last autumn, while rambling about the fields, we took 

 especial notice of the galls upon the golden-rod. We saw that there were 

 two kinds, the elongated and the round. We knew that from the former 

 came a tiny moth, well-known to us, and from the latter a fly with which 

 we were not familiar, or, if familiar, not known to come from this gall. 

 The elongated galls were all empty, ~but the round ones we found upon 

 examination contained each a small white grub. We gathered a quantity 

 of the galls and placed them in a jelly glass on the writing table where 

 they would be constantly before us for observation. 



On the following twenty-first of April we noticed something peculiar 

 about one of the galls. There was a movement at one little spot that 

 soon looked like a tiny drop of water. We were on the alert instantly, 

 and with microscopes in hand awaited developments. Upon closer 

 investigation the " drop of water " looked more like a membranous 

 bubble (ptilinum, I think is the correct term for this sac-like organ). 

 With the naked eye it could be seen to expand and relax, and upon it 

 were observed tiny drops of water or some liquid substance, — sweat 

 drops as we shall call them. 



The following is a minute description (for an amateur) of the 

 emergence of the fly as seen through a hand lens. In the first place 



