440 TRANSFORMATIONS OF INSECTS. 



minutes. It would appear, then, that the aerated fluid is not 

 taken into the tracheae. 



The mouth of this spider is a very important organ, and has 

 to do with much besides sucking and piercing. It is formed Hke 

 a beak, large, and elongated into the shape of a gutter ; and 

 it encloses part of the two piercing blades or mandibles, which 

 can unite to form a second sucker-shaped projection. The palpi 

 are hooked at the end, and enable the insect to hold on to the 

 potamogetons and other water-weeds, whence it derives part of 

 its nourishment by the aid of its piercing suckers. It eats other 

 matters, however, for the spider may be seen feasting upon the 

 flocculi, which contain myriads of animalcules and microscopic 

 plants, and which float in the water. 



Eight legs exist, and the three hinder pairs are the longest and 

 are suited for swimming, whilst the others are shorter. All are 

 furnished with two long hooked claws, which are retractile. 



M. Duges saw the females making pin-like holes in the soft 

 central tissues of the potamogetons with their beaks, and then 

 placing their eggs within, so that an opaque appearance was given 

 to the plants. The eggs are deposited in great numbers, and 

 hundreds of these oblong and reddish-brown ova are laid by each 

 female. The employment of the mouth-pieces as instruments for 

 ovipositing is very interesting. The female dies soon after laying, 

 and her body becomes flaccid first of all. She does not cover up 

 the punctures in the plant with any secretion, but leaves the eggs 

 to be protected by the cells of the plant. The larv^ of insects 

 and many worms devour the eggs, but some always remain to 

 become hatched. The egg-laying takes place towards the end 

 of May, and six weeks elapse before the larvae are hatched ; and 

 during this time the potamogeton leaves and stems die and 

 undergo decomposition, so that the newly-born spiders escape 

 without difficulty from the surrounding tissues. 



The larva; have six legs, which are placed very closely to- 

 gether, and each leg is hairy and adapted for swimming, and, 

 moreover, it is clawed. The feet are red in colour, and so is the 

 body, which is oval, flat beneath, and convex above. In front 

 are the two great eyes on each side, and between them, and pro- 

 jecting backwards, is a kind of scale. The beak looks exactly 



