412 Mr. C. O. Pai Waidn's Five Years’ Observations 
B. MISCELLANEOUS OBSERVATIONS 
ON INSECTS. 
I. APTERA: COLLEMBOLA. 
May 3, 1917.—P.S. again. If Lamborn is at Oxford I 
wonder if you'd ask him whether he ever did anything 
with curious very tiny blue-black wingless insects that 
appear at this season after the early rains. They are 
gregarious and occur in vast numbers, so that they look 
like a mass of bluish ‘“‘ soot’? on the ground, or like a 
great splash of ink. They pass over the ground in a 
wave, sometimes many yards long. I have never seen 
what I consider would be the mature forms, but I must 
send you some. When you disturb the mass they rise 
and scatter, like a film of smoke—of course, only rising 
for an inch or two above the ground. 
[Specimens collected by Mr. Lamborn at Moor Planta- 
tion (May 17, 1914) have been determined by Prof. G. H. 
Carpenter as Jsotomina 12-oculata Carp., the species 
from Nyasaland referred to below. Prof. Carpenter has 
kindly written :—] 
“ April 27, 1921.—I think that you should certainly 
publish the note, as we have so little information about 
the bionomics of tropical Collembola. This habit of 
crowding together is, of course, well known with respect 
to many British and European species—such as Podura 
aquatica on the surface of ponds, Anurida maritima on 
tidal rock pools, and Achorutes socialis on Alpine snows. 
The species of Zsotomina from Nyasaland, described in 
Sci. Proc. R. Dubl. Soc., vol. xv (N.S.), No. 39, p: 543, 
must be a markedly social insect, as there were hundreds 
of specimens in the collection, and the same may be said 
of the antarctic Gomphiocephalus hodgsoni, which the 
naturalists of the second Scott expedition found in swarms 
on frozen pools and among snow in §, Victoria Land. 
(My paper on this is now in the press among the ‘ Terra 
Nova’ reports.)” 
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