206 
Psyche 
[December 
In additional families of spiders we have found evidence of such 
an apical element; but, lacking data for both sexes, we have not in- 
cluded these data in the present paper. 
The breaking of the apical element of the male palpus is a mutila- 
tion that renders the male unable to carry out further matings. If 
the males of Latrodectus are not killed by the female after mating, 
they perish in a few days. Authors who have made detailed observa- 
tions on the mating in different species of Latrodectus , i.e. Herms 
et al. (1935), D’Amour et al. (1936), Smithers (1944), Baerg 
(1945) and Shulov (1940), do not mention that copulation was 
repeated after it had been carried out with both palpi. Herms et. al. 
(1935) says “In the laboratory the males will readily mate a second 
time, but the females do not evidence such a tendency.” Montgomery 
says “Promiscuous mating is general, a male impregnating a number 
of females, and a female receiving a number of males.” However no 
concrete evidence is cited and we believe these two remarks might 
be the result of mistaken observations. 
Of course, not all spiders have been observed to have an apical 
element. Montgomery (1909) describes in much detail the mating 
of a pair of salticids, Phidippus purpuratus Keyserling, and observes 
that the male carries out a new sperm induction every time the mating 
act is repeated. We ourselves have examined numerous specimens of 
common domestic salticids without being able to identify an apical 
element in the male palpus. 
This paper is a partial result of research that one of us (Abalos) 
is carrying out on spiders of the genus Latrodectus, under a grant 
from the Argentine National Council for Scientific and Technical 
Research. Our thanks are extended to Dr. and Mrs. Levi for help 
with determinations and with the preparation of this paper for 
publication. 
References 
Abalos, J. W. 
1955. Botnurus hertae sp. n. (Bothriuridae, Scorpiones). An. Inst. Med. 
Regional, Tucuman, 4(2): 231-239. 
Alexander, A. J. and Ewer, D. W. 
1957. On the origin of mating behavior in spiders. Amer. Nat., 91: 311- 
317. 
Baerg, W. J. 
1945. The black widow and the tarantula. Trans. Conn. Acad. Arts 
Sc., 36: 99-113. 
Berland, L. 
1932. Les arachnides. Paris, 481 pp. 
Bhatnagar, R. D. S. and J. E. Rempel 
1962. The structure, function, and postembryonic development of the 
male and female copulatory organs of the black widow spider 
