170 A NATURALIST IN BORNEO 



Singapore, but eventually died. As in the case of the 

 Lycid larvae, it is not certain what these creatures feed 

 on, but they seem to thrive if always kept moist and 

 surrounded with plenty of rotten wood. 



It may be observed that neither on Kina Balu nor 

 in the neighbourhood of Kuching, where "Trilobite- 

 Larvae " also occur, does there exist, so far as is known, 

 a Malacoderm beetle that could possibly be regarded 

 as the adult of either of these larvae, and this in spite of 

 the fact that in the one place the larva is extraordinarily 

 abundant and in the other common enough. I once 

 put forward, in conversation with coleopterists, a 

 suggestion that these larvae underwent no metamor- 

 phosis at all, but that they merely grew in size, and 

 when they attained full growth reproduced their kind, 

 or in other words became adult without metamorphosis. 

 The suggestion was scouted as too improbable to 

 deserve discussion, but a consideration of the meta- 

 morphosis of some other Malacodermata, and an 

 examination of the internal anatomy of the larva, 

 convinces me that the suggestion may eventually be 

 shown to be not very wide of the actual truth. 



A very remarkable South American Malacoderm, 

 Phengodes hieronymi, 1 is in the male sex completely 

 winged, and quite a normal beetle, but the female is 

 externally indistinguishable from the larva. Dr. Annan- 

 dale is inclined to believe that the same is true of 

 a common Fire-Fly, or Glow- Worm, of Calcutta, Luciola 

 vespertina. These two beetles, Phengodcs and Luciola, 

 belong to two different families, and consequently there 



1 Mr. Gahan informs me that nearly all species of Phengodes have 

 larva-like females and winged males. The species referred to in the 

 text is figured in Sharp's Insects, Pt. II. (1899), p. 249. E. B. P. 



