1897.] Entomology. 353 
was more primitive. The diminution of streams, ponds and morasses, 
as well as the pollution of streams, have been taken to be sufficient 
causes for their reduction. The unusual conditions for 1894 and ’95 
naturally lead us to inquire if any light has been shed on the question. 
What, then, have been the observed results? So far as my observa- 
tions have gone, and I have been much in the field, there is no evi- 
dence in the line expected. Odonata in the region included in these 
notes have been unusually abundant during the summer of 1896. No 
species hitherto taken in any abundance has been missed, while several 
not before taken at all have been abundant. This was unlooked for. 
Possibly my records indicate this, that the usual abundance in early 
spring and summer was in the vicinity of perennial waters, and that 
about the transient ones they were fewer than the normal number; it 
is certain that all of the six or seven additional species taken were 
found in the vicinity of such streams and ponds. 
“The consideration of the foregoing facts and the conditions which 
seem to have influenced them leads to a possible clue to the causes. 
Life of all kinds, plant and animal, in the restricted and concentrated 
waters of the dry seasons, were excessively abundant. The predacious 
odonate larvae, so long as any moisture remained, would be in clover; 
but when the water entirely disappeared, what ? 
“ Unfortunately, there are no records at hand in regard to ability to 
remain in the mud or within capsules of earth at the bottom of dried- 
up ponds. Other animals and some large larvae are known to do so. 
Why not also the larvae of Odonata? If this fact was proven it would 
easily explain the unusual abundance of dragon-flies this present sea- 
son in place of an anticipated dearth. Again, the eggs of some species, 
certain species of Diplax for example, do not hatch immediately, and 
therefore, may remain in the dust or mud until the autumn rains or 
until spring. In this connection I may state that Diplax rubicundula 
and D. obtrusa have been seen industriously ovipositing among the 
grass and weeds overgrowing dry ponds and ditches. Eggs thus scat- 
tered would certainly have to remain without immersion among dust 
and rubbish, in some instances, for weeks. The female of Lestes rec- 
tangularis has been seen ovipositing in stems of Scirpus and Spargan- 
ium where no water remained in the marsh and surely did not return 
for a month. It would appear from these incomplete observations that 
the nymphs of Odonata may and probably do readily pass the trying 
times of drouth unharmed. 
_ “ Third—Records made this summer have confirmed conclusions of 
former years that southern forms extend their range on the western 
