330 HELIX HORTENSIS. 
* 
The radula of an adult specimen from Maine, U.S., prepared and figured by 
Prof. Morse, showed 116 transverse rows of teeth, with 65 in each row, making a 
total of 7,540 teeth on the whole membrane. The median row is symmetrical and 
unicuspid, but modification quickly commences, as a distinct ectocone is shown on 
the eighth lateral, the teeth gradually merging into tridentate marginals, shown 
by the bifurcation of the mesocone, which is figured on the sixteenth tooth. 
Fic. 387. Fic. 388. 
Fic. 387.—Representative teeth rom the radula of an American specimen of Helix hortensis, 
highly magnified (after W. G. Binney). 
Fic. 388.—Representative teeth from the radula of an adult 7. Aortensis, from Maine, U.S.A., 
highly magnified (after Prof. Morse). 
Reproduction and Development.—Practically there is no available 
information as to the conjugation of this species or of the amours which 
precede them, but they probably differ only in detail from those of the 
larger and better known allied species. 
The colourmg and markings of the snail, if not Epigamic, as suggested 
by Dr. Beddard, have doubtless some interesting significance, though the 
probability of colour and markings exercising some sexual influence is 
shown by Dr. Gain, who observed ‘that in captivity a distinct preference 
was manifested for pairing with others similarly coloured to themselves. 
The eggs are perfectly oval in shape, about 3 mill. in length, and 2$ 
mill. broad, with an opaque-white and slightly glossy caleareous envelope, 
bestrewn with innumerable microscopic agama) crystals ; they are laid 
in clusters all through the milder 
months of the year and buried by 
the snail in the moist earth at the 
base of walls or the roots of shrubs 
and grasses; the young mollusks 
hatch out in from ten to twenty 
days, and attain maturity usually after their first hibernation, but the 
shells hatched in autumn do not attain full growth until towards the 
end of the summer following, and though potentially capable of surviving 
to an age of seven, eight or more years, it 1s probable that the bulk of the 
individuals die or are destroyed during their second or third hibernation. 
Prof. A. Lang’s experiments in inter-crossing the various varieties of 
H. hortensis showed that the 5-banded form breeds true, while the unbanded 
forms yielded unbanded progeny with a tendency to develop banding. 
When unbanded and 5-banded forms are mated the progeny may be 
unbanded or nearly equally banded and unbanded. 'I'hese variations in the 
results may be possibly due to the influence of the ancestral germ-plasma 
or even to a previous conjugation, as Lang affirms that after a single 
congress an individual has deposited fertile ova for three successive years. 
The mating of 1. hortensis with H. nemoralis was only successful in a 
single instance, and this was between a 5-banded HZ. nemoralis and an 
unbanded //. hortensis, the seven offspring of this union bearing shells which 
were Intermediate in size between the parents, but of much greater altitude, 
and all were unbanded, with a lip the size and shape of //. hortensis, but 
darkly pigmented as in H/. nemoralis, representing H. hortensis var. fusco- 
lubiatu, but no information is given of their gypsobela or “‘love-darts.” 
Fic. 389.—Section of a follicle of 
the ovotestis showing the genesis of 
the germ cells, the ova on the walls 
and the sperm cells in the lumen of 
the caecum (after Jeffrey Bell). 
o. developing ova; s. developing 
spermatozoa or spermatoblasts. 
