408 Dr. Wallace on the Oak-feeding 
that, though the details of the culture are not sufficiently clear, 
probably from faults of translation through three languages, and 
also from the desire evinced by the Japanese to mislead all inquiry 
and so protract the period during which they monopolize this 
valuable race, yet that a similar method might be employed in our 
own climate, varied somewhat to meet the exigencies of different 
localities and temperatures. One great climatic difference exists 
between ourselves and Japan, viz., the rainy season which is spoken 
of in the Manual as commencing on the 5th of May. I have 
been informed by those who have resided in Japan, that about 
that time it rains regularly and without intermission heavily for 
several weeks; this coincides with the account given “ that during 
the rains the boughs keep quite fresh.” It would therefore seem 
that at least rainy seasons are favourable to the Yamamai larve, 
and this point is the only one which seems to me to throw any 
doubt on the probable success of the cultivation of the worm 
in Europe. Ireland would, therefore, seem to be a country spe- 
cially favourable; for the same reason the north-west coast of 
England and Scotland, as perhaps also the south-west coast, would 
be specially favourable ; whereas the eastern counties are probably 
the worst. It certainly from the Japanese Manual seems that a 
very simple and easy method of cultivation is required to rear 
this worm, and thereby produce a silk of great value and lustre, 
equalling the very best mulberry silk. It would therefore in this 
case doubtless pay well to enclose oak trees kept not higher than 
12 or 18 feet, with a canvass protection, and therein rear in open 
air these valuable worms. It would seem, too, from the dates 
mentioned, viz., from the 22nd April to the 12th May, that the 
spring of the year must be as cold in those regions as in England, 
and colder than in France, since according to experience in the 
latter country, it would be difficult to retain the eggs for hatch- 
ing to so late a period, owing to the temperature rising up to 60° 
or 70°, F.; whereas in my experiments the eggs were easily kept 
to the 26th April without hatching, at which time the young leaves 
were bursting in the lanes. 
It would therefore seem, that a cold and wet temperature is 
favourable to this worm, whereas a dry warm atmosphere is best 
suited to the Ailanthus moth. This is in some degree advanta- 
geous to the prospects of sericiculture in Great Britain and else- 
where, as conferring equal if not greater advantages on those parts 
of the country which may be thought unlikely, from the habitual 
