128 Mr. F. Merrifield’s Report of Progress in 
Mr. Galton, so far as they bear on his studies in heredity. 
In this paper I propose only to give a résumé of facts 
observed in the different broods, for the information of 
those who are interested in investigations of this nature. 
All the moths have been preserved, and are labelled, and 
I have brought with me some specimens of the various 
broods. It will be seen that in the case of the forced 
ullunaria I have had to do with as many as five successive 
generations in the year. In speaking of a “‘ generation”’ 
or ‘‘brood’”’ I reckon it as beginning with the egg; in 
this sense I have had to do with the first generation only 
in its latest, winged, stage. It is proper to remember 
that the succession of broods would have been still 
more rapid than it has been had I paired off the moths 
as soon asI had a couple; the delay necessary for 
making a selection added about a week of time. I have 
had actual experience of the following periods—ege 
7 days, larva 16 and pupa 8 days, pairing and laying 
2 days, total 83 days; and I am satisfied that it wouid 
be possible to run a generation through from egg to egg 
in 35 days. 
I exhibit a diagram,* which will be a guide to the 
observations that follow, and will save much detailed 
description. It shows the connection of all the broods 
reared, and marks the extreme duration of life in the 
ege, larva, and pupa, and the duration of life in the 
moths from the time that the first appeared until the 
selection was made for breeding from. The moths so 
selected generally lived from 7 to 14 days; the others. 
were killed and preserved. 
THE EXPERIMENTS WitH §. mLLUuNARIA.—The spring of 
1887 was, as all will remember, a singularly cold and 
backward one. No illwnaria were taken for me till 12th 
April. I bred from two females taken near Brighton on 
the 29th April and 2nd May respectively by Mr. A. C. 
Vine, who kindly gave them to me, and from two females 
taken on the 2nd May in the New Forest by Mr. Charles 
Gulliver, of Brockenhurst. They laid from 48 to 133 
eggs each. Some of the eggs laid by them were used 
for preliminary trials. There were 271 left. I divided 
each of the four batches into three, and, mixing together 
one-third from each batch, obtained three lots of 90, 90, 
" * See Plate V. 
