LEPIDOPTERA. 243 
of all sorts, not less useful than the silk derived from this tree.” 
Olivier de Serres proves in this memoir that the second bark, or 
liber, of the mulberry tree contains a fibre capable of replacing 
hemp or flax, and he describes the processes by which this may 
be obtained. The processes which had been proposed by Olivier de 
Serres in 16038, were-resumed in the Cévennes a dozen years 
ago by M. Duponchel on the one hand, and on the other by 
M. Cabanis,* who operated on bark instead of taking the whole 
of the wood of the mulberry tree. But none of these attempts 
have given any good results up to the present moment. 
The various diseases which, for the last fifteen years, have 
been so fatal to the mulberry silkworm, have suggested the idea 
of acclimatizing in Europe other silk-producing Bombyces, if not 
with the view of superseding, at least as auxiliaries to the mul- 
berry species. The genus Aftacus has furnished these auxiliaries. 
Among the species which have, in this respect, the greatest 
claims to our attention, we must place in the first rank those 
which feed upon the leaves of the oak tree. Indeed, the trees 
‘which can be made use of for their cultivation are very numerous 
in Europe, and, moreover, the silk produced by these worms appears 
to possess superior qualities. 
There are three oak-feeding species of the genus Attacus. They 
are Yama-Mai, Pernyi, and Mylitta. 
The silk of Yama-Mai is as bright as that of the mulberry silk- 
worm, but a little less fine and strong, and occupies the first rank 
after it. If we could succeed in acclimatizing this species it would 
supply any deficiency there might be in our crops of ordinary 
silk. 
The eggs of the Attacus Yama-Mai were brought from Japan, 
where this worm is reared, conjointly with the mulberry silk- 
worm, in 1862. The larve hatched at Paris, in 1863, were 
green, of a great size, remained in that state eighty-two days, 
and were easily reared. Their cocoon resembles that of the 
mulberry species. It is composed of a beautiful silk of a silvery 
‘whiteness in the interior, and of a more or less bright green 
on the exterior. The moth is very large and. beautiful, of a 
bright yellow colour, approaching orange. 
* See our “ Année scientifique,” 7e année, p. 432. 
R2 
