ANATOMICAL NOMENCLATURE. 131 
that of a passive organ, receiving the sperm and transmitting it into the 
genital cleft of the female under the pressure of the blood which enters 
into the heematodocha through the meati sanguinis. 
The receptaculum, in the region of the embolus, is throughout its whole 
length fine, smooth, and without pores. Further toward its closed extremity 
is a mass of minute ducts which pierce the walls, and which 
eee Wagner has named meati sanguinis, blood ducts. All spiders 
are provided with these ducts, and their role is to serve as con- 
duits to the blood from the hematodocha into the receptaculum. 
The Tegulum is a quite thick plate of chitine serving to cover in from 
above and to protect the receptaculum. Many spiders, as the Attids, Thom- 
isids, and others, have here no chitinous conformation except the tegulum ; 
but spiders which have a more complicated organism of this apparatus 
are provided with many other auxiliary organs, in the form of lamine, 
dentations, and excrescences of the most unique and yaried forms. The 
embolus is an organ of a chitinous nature, for the most part subiliform or 
having the form of a switch. At its extremity there is a small orifice 
(Fig. 98, or), by which the sperm enters and issues. The articulation of 
the embolus with the tegulum may be mobile or immobile. 
The action of the above parts is as follows: The male applies to the 
genital cleft of the female the exterior face of his palp, and by numerous 
The Role contractions of the abdomen, in which the subcutaneous muscles 
‘take part, forces the blood through the orifice into the cavity 
of the hematodocha, which it expands, pushes out the copulatory appa- 
ratus, and having by way of the blood ducts penetrated into the cavity 
of the receptaculum seminis, impels the sperm through the embolus into 
the genital cleft of the female. When the blood begins to abate, returning 
into the body of the male it fills anew the sac as full as at first, an opera- 
tion which is repeated until fecundation is terminated; then the palp is 
withdrawn from the genital cleft, the hematodocha contracts, and the 
tegulum resumes its position.1 
‘La Mue des Araignées, M. Waldemar Wagner, Ann. Se. Nat. Zool., 1888, 367-371. 
