Popular Science Monthly 



369 



attack of different species of parasites at 

 dilTereut stages in their development, it 

 has been necessary, in order to secure all 

 of these, to import the host insects in as 

 many different stages as possible and 

 practicable. Importations of large cater- 

 pillars, ready or nearly ready to pupate 

 (go into a sleeping state) were first 

 made in 1905. It was demonstrated 

 during that year that they 

 could be broug 

 America with a 

 degree of succc 

 and that at least a 

 proportion of the 

 parasites with 

 which they 

 were infested 

 could be 

 reared. 



One of the 

 greatest diffi- 

 culties, experi- 

 enced from the 

 outset, has 

 been the ac- 

 cl imatization 

 of the parasites. 

 The ones thus 

 far cultivated 

 have a tendency toward rapid dispersion 

 over a wide area, thus hindering coloni- 

 zation. Even though a large number of 

 individuals are released, their spread is 

 so rapid that the possibility of meeting 

 and mating is soon lost. 



Perhaps the most serious handicap to 

 the progress of the work is the preserva- 

 tion of the health of the assistants in 

 the laboratory. The irritating and 

 poisonous hairs of the brown-tail larvae, 

 of which the nests are full, penetrate 

 the skin of the assistants, entering their 

 eyes and throats and almost filling the 

 atmosphere of the laboratory. It was 

 soon found necessary to keep the rooms 

 thoroughly closed. Double windows were 

 used, and the doors, too, were doubled, in 

 order that a possible secondary parasite, 

 if accidentally liberated, should have no 

 chance of escape. This made the rooms 

 very warm and increased the irritating 

 effect of the larval hairs. Spectacles, 

 gloves, masks, and even headpieces were 

 invented, but they only increased the 

 heat and were not entirely effective in 

 keeping out the troublesome hairs. 



Spectacles, Gloves and Masks Are Worn by the 

 Laboratory Workers as a Safeguard Against 

 the Irritating Effect of the Gypsy Moth's Hairs 



Dr. Fiske finally devised an apparatus 

 similar to an ordinary show case, the 

 glass in one side being replaced by cloth 

 with armholes, through which the gloved 

 hands ol the worker could be thrust and 

 the brown-tail nests handled in full 

 sight through the top glass. Much of 

 the rearing of brown-tail larvae must be 

 carried on under conditions in which 

 such cases cannot be used, 

 the old difficulty 

 exists. 



is hoped that the 

 ;)arasites already 

 introduced will in 

 time prove 

 sufficient for 

 the purpose 

 intended. Only 

 events them- 

 selves can be 

 depended upon 

 to answer this 

 question. Un- 

 fortunately the 

 mothscontinue 

 to disperse 

 and multiply 

 in the mean- 

 time. 



Why Whiskers Continue to Be in 

 Style for Cats 



ALTHOUGH hirsute adornments of 

 ,. all kinds, whiskers included, were 

 once the real and indispensable thing, 

 modern sanitary practice has made such 

 inroads on unharvx\sted beards and long 

 hair that only a few scattered humans 

 such as musicians and soap-box orators 

 still retain their hairy luxuriance. Not- 

 withstanding this, however, the house 

 cat has grown and nurtured its crop of 

 whiskers or feelers for the last million 

 years or so without bothering about 

 hygiene. 



The fact is that the cat's whiskers are 

 absolutely necessary to it. The whiskers 

 are as long as the cat's head is wide, and 

 the head is as wide as the body, so 

 wherever the whiskers go there may the 

 cat go also. 



The tiny, delicate hairs grow from a 

 gland and are nerved to the utmost 

 sensibility. No matter how light the 

 touch of the hair against an obstacle it 

 is instantly felt by the cat. 



