21g Dr. Wallace on 
eggs laid from July Ist to July 10th; these hatched out and passed 
through their first two moults in this nursery and then, beginning 
August 3rd, were transferred to the larger Ailanthery, where they 
finally fed up and spun their cocoons, The nursery was not 
covered in or protected in any way, except that in order to pre- 
vent the ants from getting at the young larve (which they will 
carry off ), 1 surrounded the stems of the trees with cotton wool ; 
this, however, proved a great embarrassment to those larvae which 
fell to the ground, as it hindered them from re-ascending the 
trees, and I shall not repeat it another year, though I must add 
I did not see any ants about the trees till after the cotton wool 
was all gone. It is however just possible that the cotton wool 
operated as a protection to the silkworm in an indirect way. For, 
watching over the dwarf wall and from the windows of the house, 
I frequently saw sparrows who had occupied some nests which the 
swallows built under the roof (having driven those birds away), 
fly down hastily to the little garden, pick off a piece of wool and 
return to their nest. It may be that their attention was fixed 
upon cotton wool, and a guilty sense of thieving hurried their 
actions, so that they failed to observe the young larve feeding 
just above their heads; anyhow, I never could observe that they 
committed depredations on the larvee, though I frequently watched 
them by means of an opera-glass for the purpose of detection. 
The larger Ailanthery was planted on a narrow strip of ground 
about a rod wide, running for half a mile along a branch of the 
Great Eastern Railway. Just after the branch leaves the main line, 
it makes a sweep back towards the town of Colchester; in this 
sweep, protected from the north and open to the south and west, 
runs a narrow strip of ground, intended for a second set of rails 
when needed. Here were planted in 1863, in March, 3,000 two- 
year old Ailanthus trees obtained from France. About 700 were lost 
that year, owing to the prolonged drought in the spring; the rest 
made little progress that year, The soil is a deep rich loam, 
very sticky and plastic in wet weather ; the trees were planted 2 
feet apart, in rows some 2 feet distant, some 3 feet, some 4 feet. 
Of these trees about 1,340 were sufficiently luxuriant in 1865 to 
allow of a crop of silkworms; many of their shoots were from 6 to 
8 feet along, and an inch in diameter. Hither the young larvae, 
when half-grown, were brought down in boxes, and distributed 
over the plantation, allowing from 5 to 10 to each tree according 
to its luxuriance. In order to convey them, the entire leaf on 
which they rested in the morning was cut off the tree, and the leaf- 
stalk cut up into leneths, depending on the number of worms 
