EARLY DEVELOPMENT OF JULUS TERRESTRIS. 449 
The Early Development of Julus Terrestris.' 
By 
F. G. Heathcote, M.A., 
Trinity College, Cambridge. 
— 
With Plates XXIII & XXIV. 
My investigations, the results of which are contained in the 
following paper, were begun in June, 1882. I collected a 
number of Chilognatha and kept them in glass jars, the bot- 
toms of which were covered with damp earth. I soon found 
that Julus terrestris® was the species best suited for my 
purpose, as though the eggs presented some difficulties not 
present in the eggs of other species, yet they were of a conve- 
nient size and were easily to be procured in great numbers. 
I fed the animals on sliced apples and occasionally on green 
leaves, and this diet seemed to suit them well, for I never failed 
to get several clumps of eggs in the breeding season, though 
it is only this summer that I succeeded in getting them in any 
number. The breeding season of these animals lasts from the 
end of May till the end of August, though the weather has a 
considerable influence on the time when they begin and leave 
off breeding. I have observed copulation, which takes place 
exactly as described by Cuvier (‘ Régne animal,’ 3rd edit., 
1836, vol. ii, p. 330). I was unable to determine how long a 
time elapses after copulation before the eggs are laid, but believe 
it to be short. About four days before laying her eggs the 
1 The numbers in brackets in the text refer to the list of papers at the end. 
2 The species was kindly identified for me by Mr. T. D. Gibson Carmichael, 
F.L.S., as Julus terrestris, Leach. 
