620 



THE POPULAR SCIENCE MONTHLY. 



The cause of the fly becoming so firmly attached to dry surfaces is 

 this : The two pulvilli which, with two strong curved claws (perhaps 

 best seen with the flesh-fly, Musca vomftoria, as a subject), terminate 



Fig. 4 Maggot op House-Flt, July 29, 1878, x 25. 



the foot, are surrounded by a fringe of tubular hairs, each ending with 

 a disk or sucker, through which a glutinous fluid exudes. These form 

 the points of attachment, enabling the insect to walk in any position, 

 the action of the two claws detaching these points as the fly moves 

 along. 



When the ravages of the parasite have sufficiently weakened the 

 fly by the destruction of its viscera, etc., it becomes incapable of active 

 movement, and, remaining too long in a place, the viscid fluid continues 

 to exude, and then the fly " sticks to the wall." Science Gossip. 



FOOD AND FEEDING. 



By Sib HENRY THOMPSON. 



III. 



I HAVE already said that, among all civilized nations, wine in 

 some form has for centuries been highly appreciated as a gastro- 

 nomic accompaniment to food. I can not and do not attempt to deny 

 it this position. Whether such employment of it is advantageous from 

 a dietetic or physiological point of view is altogether another question. 

 I am of opinion that the habitual use of wine, beer, or spirits is a die- 

 tetic error, say, for nineteen persons out of twenty. In other words, 

 the great majority of the people, at any age or of either sex, will enjoy 

 better health, both of body and mind, and will live longer, without any 

 alcoholic drinks whatever, than with habitual indulgence in their use, 

 even although such use be what is popularly understood as moderate. 

 But I do not aver that any particular harm results from the habit of 

 now and then enjoying a glass of really fine, pure wine and, rare as 



