1963] 
Abalos and Baez — Spermatic Transmission 
199 
it is suggested that the proto-spiders may have transferred the sperm 
to the female by way of a spermatophore which they deposited on 
the substratum. The pedipalps may initially have assisted in this 
operation or have merely held open the female genital aperture. It 
is further suggested that the loss of the spermatophore and retention 
of the pattern of deposition of the spermatic fluid are to be cor- 
related with the evolution of web-spinning.” 
Equally numerous authors have studied the morphology of the palpi 
of male spiders, attempting to interpret the functions of its different 
components. The most important paper is one by Comstock (1910), 
who described palpi of varied complexity, the simplest being that of 
the cosmopolitan spider Filistata hibernalis in which the widened 
palpal tarsus forms a kind of bulb containing the coiled blind duct. 
The most complex structures are possessed by the Argiopidae. Since 
1953, Levi has described in detail the male palpal apparatus in various 
theridiid genera and lately (1961) he has studied the evolution of the 
development of the palpal sclerites in this family. He supposes that 
in these spiders the simplest palpus is primitive and that the more 
complex ones indicate a higher degree of evolution. 
As to the interpretation of the function of the different parts of the 
bulbs, authors do not agree with each other; some even believe that 
these organs have lost their function but still persist. Berland (1932) 
says: “During copula certain parts of the bulb have an important 
role; the accessory pieces, apophysis of the bulb, the tibia, and the 
patella, crest of the tarsus, etc., seem to be a completely unnecessary 
luxury; the attempts made to find a role for each of these parts rest 
upon the preconceived idea that each organ must have a function.” 
The different authors who have been interested in this subject 
do not provide a clear answer to the problem of exactly how the 
transmission of the sperm from the male palp to the female seminal 
receptacle is carried out. Equally it is not well established how sperm 
enters the bulb during sperm induction and how it is expelled during 
copulation. 
Explanation of Plate 21 
Figs. 1-3. Latrodectus geometricus. Fig. 1. Seminal receptacle with male 
apical element. Fig. 2. Place of separation of apical element. Fig. 3. Complete 
embolus. -Baez del. 
Figs. 4-11. Metepeira sp. Fig. 4. Seminal receptacle with male apical 
element. Fig. 5. Seminal receptacle with two apical elements. Figs. 6, 7. Loca- 
tion of apical element in the palpus — Argiopid species. Fig. 8. Seminal 
receptacle with apical element. Fig. 9. Apical element — Metepeira Candida. 
Fig. 10. Seminal receptacle with apical element. Fig. 11. Apical element. 
-Baez del. 
