FARMERS' IXSTITUTES. 169 



suppose they would desire fresh air, shut up in such abodes. The larva matures 

 about May or June, when it is f ally an inch in length, backs out of its filthy 

 chamber and falls to the earth. The abscess soon heals. 



The insect, like all of this family, pupates in the ground, the pupa differing 

 only in size from those already described. 



Effects on Cattle. 



These seem to cause little inconvenience. In fact it is not uncommon to see 

 the sleekest cow or ox thickly covered with these tumors. While they seem to 

 do no serious damage, I am still of the opinion that the cattle would be quite 

 as well off were they rid of these parasites. The worry caused by the torment- 

 ing presence of the flies is certainly an evil. 



Hemedy. 



I am unable to suggest any method to remove this enemy. Of course the 

 evil may bo abated by pressing the maggots out of the tumors, but as this will 

 never be so generally practiced as to eradicate the pest, it is plainly impractica- 

 ble. We can only rejoice that the disadvantage is so slight. 



There are many other species that form tumors on different animals, very mucli 

 as described above, only one of which I will mention : the Cuterehra emascula- 

 tor, Fitch, which infests tlie squirrel. The eggs are laid on the scrotum of the 

 animal, and the bots not infrequently produce effects Avhich suggested the spe- 

 cific name. There is no question but what many of these animals have died in 

 our State because of this enemy. 



Following Prof. Cook's paper several Questions were asked and answered as 

 follows : 



Mr. Henry Greene. — "Is there any season when the horse is free from the 

 bots?" 



Prof. Cook. — "The probability is tiiey may be found in the horse at any sea- 

 son ; still the horse may be without them early in the year, just before the season 

 of the perfect insect." 



Mr. S. Satterlee. — "Does not the fly in laying the eggs, even if she does not 

 probe the horse, irritate by pulling the hair?" 



Prof. Cook. — "It is my impression that the irritation of the animal is from 

 nervousness rather than any thing the fly may do, except buzz. When a boy 

 I would jump if I stepped on a round stick, because of my excessive dread of 

 snakes, and I apprehend that this is the best way to account for the dread the 

 horse has of bot-flies." 



Mr. James Taylor. — "Are not the bots licked into the mouth while eggs and 

 hatched within the animal?" 



Prof. Cook. — "This is quite probable, but I think the most usual way they 

 get in is by first hatching on the outside and by stirring around cause irrita- 

 tion, which the horse tries to relieve with the mouth, and in this manner cap- 

 tures them." 



Mr. Bradish. — " You recommend clipping the hair of horses having bots' eggs 

 upon them. Will not their eggs hatch that are thus cut off?" 



Prof. Cook. — "With suitable conditions of warmth and moisture, yes; but 

 there is no danger from these, as there is no chance of their getting where they 

 can have any thing to eat before they die. I would like to ask a question of the 

 audience: " What is your impression about the cattle bots, — do you find them 

 most frequently on the backs of fat or lean cattle?" 



22 



