1925] Mystery of “Trilobite Larvce ” Definitely Solved 125 
After some weeks of captivity one of the larvae rolled itself up 
and was lying on the surface as though dead for several days. 
One morning I found that it had cast the larval skin and ap- 
peared quite whitish. It remained in that position for another 
five days whereupon the color changed into a dull yellowish- 
white. It soon started to crawl slowly about. A close exam- 
ination revealed the interesting fact that it had developed a 
sexual opening on the eighth sternite surrounded by two small 
valves immediately in front of the anal suction disc. 
Some days later on it started to lay eggs. These were small, 
whitish, perfectly round, measuring about one millimeter in 
diameter. They were deposited in small groups here and there 
or simply dropped wherever the female was crawling, sometimes 
as many as 15-20 at the same place. Egg-laying went on for 
about two weeks until over 300 eggs had been deposited. Every 
morning, when opening the door to the cage I found the female 
turning the top of the abdomen upwards in order to expose the 
sexual opening from which a clear drop of liquid was secreted. 
Three more larvae cast skins after a similar period of rest 
and turned into sexually mature females behaving in exactly the 
same way as the first one described above. They all died after 
having deposited from 300-400 eggs. Some months later more 
females developed, but no signs of any males could be seen. 
In October I undertook a new expedition to Mt. Poi in 
Southern Sarawak. There I came across the very same big 
black larva just referred to. They were found at an altitude 
ranging from 3000-5000 feet and were quite numerous. Several 
developed into females and were exposed at suitable places in 
the jungle in hopes of attracting the males, but without success. 
The females were tied up with a string long enough to allow 
them to move about in a circle and were protected by a cage of 
wire netting with meshes more than an inch wide. Thus the 
males could easily gain access to the cages and the females were 
comparatively free but at the same time well protected. 
All efforts were, however, in vain. I had to return again to 
my headquarters. During the following month (December) my 
native collectors brought me more than 200 big larvae of the same 
type from another mountain, Batu Gadin, in the Lundu district, 
