198 Dr. Wallace on 
40 inches; in the hectare there were 50 rows, each 80 inches 
apart from one another, and 100 metres long; the trees were 
planted 900 a-day, by plunging the spade into the soft ground, 
pressing it forward, and slipping the plant into the crevice behind 
the spade. 
50 rows of 100 metres=5,000 metres in length. 
5,000 metres in length at 245 centimes .. 125 francs. 
Planting 900 trees per day, 6 days, at 3 
francs per day .. oe es apne aull Oak nage 
5,000 trees at 15 francs the thousand a, lta oaias 
6 hectares=15 acres, nearly ........Total 218 francs, or 
about £8: 15s. 
Such an account of the expenses of planting seems almost too 
favourable for belief, and could only be obtainable in very light 
soils. 
In describing the domestic habits of Bombyx Cynthia, it will 
perhaps be the most convenient to begin with the winter life, and 
trace its progress through the various seasons of the year. It 
remains through the winter in the cocoon, whereas Bombya Mort 
passes that season in the egg state. My cocoons are now strung 
up in rows or chaplets of 50 or 100 each, threaded on twine and 
suspended in a room for the winter : or they may be kept in clothes- 
baskets or bags: they may however hang out of doors on the 
trees. Every winter I allow a few cocoons to remain hanging 
where spun. In the succeeding summer these produce large 
healthy moths, but at a later period than those housed, since the 
colder temperature to which they are subject during the winter and 
spring retards their development. Consequently, if (in order to 
provide for a second brood) it is wished to hatch out the moths 
early in the spring, the cocoons must be kept housed during the 
Winter at a temperature of 40°—45° F., which, towards the end of 
February, should be raised to 60° F. (in a kitchen or green-house), 
and in March to 70° or 80° F., when the moths will emerge in 
April ; their progeny will in England, in ordinary seasons, emerge 
from the cocoons in time to allow another generation to spin their 
cocoons. In order to provide food for the early larve so forced, a 
few Ailanthus trees in pots should be placed in a green-house, 
so as to provide foliage in April, and during the first and second 
week in May, after which time the trees in the open air have 
plenty of leaves. 
By this plan in 1865 Lady Dorothy Nevill obtained eggs in 
May, and was thus enabled to rear a second brood, whose cocoons 
