XIII APPEN DAGES 3 
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iis 
tube within the bulb, ending in a blind sae, the “ receptaculum 
seminis,” which projects into the haematodocha; and it is the 
aperture by which the sperm both enters and leaves the organ. 
How the sperm is conveyed to the receptaculum was long a 
matter for speculation, after the belef in a direct communica- 
tion between the generative glands and the pedipalpi had 
been abandoned. The process has been actually observed in the 
case of a few spiders, which have been seen to deposit their 
sperm on a small web woven for the purpose, and then, inserting 
the styles of their palpal organs into the fluid, to suck it up into 
the receptacula seminis. This is probably the usual method of 
procedure, though it may be true, as some have asserted, that the 
palp is sometimes applied directly to the genital orifice. 
The receptaculum and its tube being thus charged with sperm, 
it is the function of the haematodocha to eject it by exerting 
pressure on its base. For this purpose the haematodocha is in 
communication with the cavity of the tarsus, from which, in 
copulation, it receives a great flow of blood, and becomes greatly 
distended. Bertkau believes that he has detected very minute 
pores (meatus sanguinis) communicating between the haemato- 
docha and the receptaculum, and allowing some of the blood- 
plasma from the former to mingle with the semen, but this 
appears to be very doubtful. 
The Legs are uniformly eight in number, and are seven- 
jointed, the joints, counting from the body, being the cozu, 
trochanter, femur, patella, tibia, metatarsus, and tarsus.’ In a 
few cases, through the presence of false articulations, @.e. rings of 
softer chitin, this number appears to be exceeded. Some of 
the Palpimanidae (see p. 398) were at first thought to have 
only six joints on their anterior legs, but the tarsus is present, 
though very small. 
In the case of most spiders, the legs take a general fore and 
aft direction, the first pair being directed forwards, the second 
forwards or laterally, and the third and fourth backwards. In 
the large group of “ Crab-spiders ” (Thomisidae), and in many of 
the Sparassinae, all the legs have a more or less lateral direction, 
and the spider moves with equal ease forwards, backwards, or 
sideways. The legs are usually more or less thickly clothed 
1 Pickard-Cambridge, in his Spiders of Dorset, names them exinguinal, coxal, 
femoral, genual, tibial, metatarsal, and tarsal. 
