334 



THE MICROSCOPE. 



the haustellate the lowest position in the order : thus confirming to 

 some extent the observations made by Mr. Denny. 



There is a remarkable species of acarus described by Dr. Robins, 

 found spinning a white silky web on the base of the sparrow's thigh, 

 or on the fore-part of its body ; on raising this delicate web, you per- 

 ceive that it is filled with minute eggs, from which the young issue, 

 being in due time hatched by the warmth of the body it is destined to 



fig. 163. 



1. Acarus of Beetle. 2. Acarus of Fly. 3. Acarus of Clothes-Moth. 

 The circles enclose the objects about life size. 



annoy. In fig. 160 are seen some eggs of a parasite infesting the horn- 

 bill j they were glued to the feathers near the head of the bird. The 

 insect is nearly ready to leave the egg. Another, curiously enough, 

 selects the pulmoiiic orifice of the snail : when the animal dilates this 

 orifice, for the purpose of allowing the air to penetrate its respiratory ca- 



