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Psyche 
[June 
where they had been despatched exclusively for the purpose of 
collecting “trilobite-larvae.” Of these more than 20 developed 
into adult females in quite the same way as the ones previously 
referred to. As no signs of males could be detected it became 
now more clear to me that the “trilobite-larvae” commonly met 
with in the various localities must all be female larvae. 
In January 1924 I set out for a third expedition, this time 
to the second highest mountain in South Sarawak, Mt. Pen- 
rissen (4000 feet). The main object was to follow up the search 
for the males of the mysterious larvae, all the available 
female material was brought along in two big cages. My sup- 
position that the same type of larvae probably would be found 
also on Penrissen turned out to be quite correct, for several 
larvae of the same or at least very similar kind though not quite 
so big were found in close vicinity of my camp. 
A number of newly developed females were immediately 
exposed in the same way as described before. As many as 18 
cages were kept going. They were carefully examined three 
times a day, the first time always at sunrise. But although 
over a month was spent on the big mountain, covered with a 
luxuriant jungle, no traces of any males could be found. 
It deserves to be mentioned that all “trilobite-larvae” 
found on Mt. Penrissen -were only half grown and showed more 
pronounced light markings between the dorsal rows of tuber- 
cules than the form from Mt. Dulit, Mt. Poi and Mt. Batu 
Gadin. It is therefore possible that it might have represented 
another species or sub-species and that both these facts may 
have been reasons why I did not meet with any success in 
capturing the males. 
I returned to Kuching, determined not to give up my efforts 
to secure the males. As all the larvae of the developed females 
had been collected on Batu Gadin, this place could be regarded 
as their true home and I therefore decided to move my base of 
operations there. In April 1924 I proceeded to Lundu and from 
there directly to Batu Gadin where my headquarters were erected 
at an altitude of 2500 feet. 
During two weeks I supervised the experiments myself. 
Females of the ordinary types as well as of the smaller more 
