218 RED SPIDER. 



The egg is oval, or spherical, and colourless, and may be 

 found amongst the webs on the leaves. The larva (as it is 

 called, although the name is hardly appropriate, the "Eed 

 Spider" not being an insect) is stated to hatch in about 

 eight days, and is much like the parent, excepting in having 

 only three pairs of legs in early life, the fourth pair being 

 acquired as it advances towards maturity. 



The figure (4, p. 217) of the Acarus whilst still in the egg 

 shows the two foremost pairs of legs pointing forwards ; the 

 single pair of hinder legs lying beneath the body of the 

 " spider," and pointing backwards, and the eyes are also 

 indicated by the roundish spots to the right and left of the 

 fore part of the figure. Fig. 3, p. 217, shows the characteristic 

 form of the terminal portion of the legs of the Tetranychi 

 generally, as well as of T. telarius. This, it will be seen, is 

 provided with two hooks, and each of these hooks is double 

 and more or less bent, and ended by a point which is almost 

 always very slender. At the base of the hooks, and at the 

 extremity of the foot, are four stout hairs enlarged at the 

 ends. This enlargement or caruncle has the shape of a small 

 compressible sphere resembling a cuj^ping-glass, and is of 

 service to the "spider" in walking. The preceding division 

 of the foot bears on the outside (see figure) one very long 

 hair, which reaches far beyond the extremity of the foot. 



The rostrum, which is placed in front of the body, forms a 

 conical point of some size, the anterior portion of the body 

 being advanced so as to protect the mouth-parts, of which 

 fig. 1, p. 217, shows sufficient for common purposes ; but the 

 following extract regarding the palpi is of important interest 

 in connection with the position and method of action of the 

 spinning apparatus : — 



" Underneath is the lower lip (en gouttlcre), and furnished 

 with two large palpi, which form the most voluminous and 

 the most projecting organs of the rostrum. These palpi, 

 which are multi-articulate, have at their extremity conical 

 spinules or hooks directed inwardly. They serve to direct 

 the viscous matter, which, furnished by special glands, is 

 expelled by the mouth. As it hardens in contact with the air 

 it constitutes the threads of the web." — Dounadieu, op. cit., 

 p. 138.* 



* The above point of the position of the silk-secreting glands and the duct 

 by which the thread is expelled is well deserving of attention from the various 

 views which have been advanced on the subject, and especially from its being 

 stated in Murray's ' Aptera ' (the chiefly accessible work on Acarina to most 

 English students), at p. 98, that " the threads of its web are secreted from a 

 conical nipple situated underneath, and very near the extremity of the abdomen." 

 The reader who wishes to go into the matter fully will find it entered on at 

 pp. 96-98 of Donnadieu's work referred to, from which much of the foregoing 

 information is extracted. At p. 97 it is noted that "L. Dufour and Dug^s 



