MIMICRY IN SPIDERS. 415 



Other forms. The last variety, pure pink, is inhabited by a 

 Thof7iisus, which is also pink on the dorsal side of the abdomen 

 and limbs. In fact, each of the three colour varieties of convol- 

 vulus is inhabited by a correspondingly coloured variety of 

 Thomisiis. It has been generally considered that each of the three 

 varieties is a genuine variety ; but this assumption is erroneous, as 

 M. Heckel found out. He put in a small box a number of pink 

 Thofuisus, in order to send them on to a friend for investigation ; 

 but he forgot all about the box and its contents during a fortnight, 

 and when he opened it again was astonished at seeing that all the 

 spiders had lost their pink colour. He took some of them and 

 put them on differently coloured flowers, and was much surprised 

 after four days to find each spider had taken the colour of the 

 flower it lived on. As specimens of the same Tho?nisus are often 

 found in the yellow Afitirrhiniwi and the red dahlia, he put some 

 of these coloured specimens to these flowers, and saw that they 

 assumed a yellow or red colour. The conclusion is, then, that 

 there are no real and permanent colour varieties of Tho7tiisiis 

 07iustus, but that the same animal may vary in colour according to 

 the colour of the flower it has selected as lodgings. 



This fact is very interesting, and we feel inclined to accept it; 

 but M. Heckel has not sufficiently proved his case, as he has not 

 taken care to prevent the possibility of the uncoloured spiders 

 running away and leaving the place to be taken by others. A very 

 simple experiment will easily settle the matter, and perhaps some 

 of our readers may be induced to investigate the subject with other 

 species of animals. 



Speaking of spiders, we would call the attention of the farmer 

 to a paper which M. F. Terby has recently published in the Revue 

 Scientifiqiie. M. Terby is a Belgian entomologist, and has made 

 some valuable investigations concerning ballooning or flying 

 spiders. Every one has met spiders sailing through the air, and 

 carried on long silk threads. I met some hardly an hour ago, in 

 the bright, warm October day which is closing ; and it is in 

 October, when the young spiders are hatched, that the flying spiders 

 are most commonly met with. It would seem that the latter had 

 attracted the attention of Aristotle ; at all events, it is quite 

 certain that over two centuries ago Stafford, Martin Lister, and 



