REPRODUCTn’E ORGANS — GYPS OBELTJM. 
367 
of the dart-sac, its exposed point being pressed against and slightly- 
piercing the body of the companion snail. 
Owing to the slight attachment to the tubercle the dart may he 
lost during use, and fall to the ground, or become adherent to the 
exserted organs, and be afterwards withdrawn with them into the body, 
working its way amongst the organs, and eventually becoming lodged 
in the viscera, as many as three darts have been found thus lodged 
in the interior of the body of a single animal. 
Great variation in form of the love-darts exists amongst even the 
few teliferous Briti.sh species, and a scale or series of forms from 
simple to complex may easily he constructed, showing the gradual 
modifications leading from one type of dart to another, but a start- 
© - 0 “ 
Fig. 672. Fig. 673. 
Magnified diagrammatic sections of darts of certain species of British teliferous Gastro- 
pods, showing the gradation from a simple to a complex structure. 
Fig. 672. Helix hispida L. Fig. 673. Helix itala L. 
Fig. 671. Helix aspersa Mull. Fig. 675. Helix pisana Mull. 
lingly close affinity in the shape and general character of the dart is 
exhibited by species distinctly different in general aspect, thus Helix 
lapicida and Helix arhustorum have practically identical darts, those 
of Helix aspersa and Helix nemoralis possess the same peculiarities, 
and there are other remarkable approximations in the aspect of the 
darts the animals of which, judged by their shells alone, are not very 
intimately related. 
Equally striking is the remarkably different darts sometimes 
possessed by closely allied species, those of Helix nemoralis and 
Helix hortensis being so remarkably distinct that doubtful inter- 
mediate forms of these species can only be settled with absolute 
certainty by their aid. 
Schmidt affirms a correlation between the character of the dart and 
the number of bands present upon the shell, those species with a 
pyramidal subulate dart and mucous glands of more than eight coeca 
have normally not more than five bands ; those species, like Helix 
arhustorum, with a lanceolate dart and two simple or bifid mucous 
glands, have never more than four, while two subulate curved darts 
are associated with numerous spirally arranged linear markings upon 
the shell. 
Fig. 674. Fig. 675. 
