LAND SNAILS. 113 
Dr. S. P. Woodward has in his possession “ an 
adult shell with a second half-grown individual 
fixed to its spire, and partly imbedded in the 
suture of the body whorl. The epiphragm re- 
mains in the exposed part of the small shell’s 
aperture, showing that it had died during the 
first hybernation, whilst its neighbour had sur- 
vived, and not getting free from the incubus of 
the empty house of the deceased, had partially 
enveloped it in the course of its growth to 
maturity.” M. d’Orbigny bred for many years 
im succession from a reversed monstrosity of H. 
aspersa—one of our commonest and most gene- 
rally-known snails. 
Theoretically considered, there are no useless 
animals. All the beings disseminated over the 
surface of the earth must be regarded as playing 
each their part in the economy of nature, from 
the single fact of their existence. They, by their 
incessant co-operation, maintain that admirable, 
unalterable equilibrium of the natural world. 
But practically considered it is another thing; 
and in inhabited districts a distinction arises as 
to what are the useful and what the injurious ani- 
mals Man finds around him. Against the latter, 
wrongfully or justifiably, a war of extermination 
is declared, whilst the others are surrounded by 
_ all the protection they appear to require. 
_ The agriculturist, and especially the horticul- 
I 
