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tropical distribution, it will be understood, that, as I stood there 
with the larva in my hand, I could not have been more aston- 
ished even if I had drawn forth a representative of the Dipnoi 
from the mud of the Donse pond. 
In the autumn of 1914 I made many excursions to Donse and 
I found many larvæ. Frequently I had 30—40 larvæ in my aqua- 
ria, where I had rich opportunity, of seeing the larvæ creeping'be- 
tween the roots and piercing their tubes into the plant-tissues. In 
Fig. 3. Larva in its natural position on the bottom of the aquarium, belween the 
roots and twigs of water-plants. Note the inflated, thick body. Photo. 
one of the last pages of my paper on the water insects I gave a 
microphoto (fig. 3) of the larva fixed to a root, and some draw- 
ings of the tracheal system and the sipho; better drawings of the 
objects may now be given. 
The larva (figs. 4—5) was rare; the greatest number I was 
able to procure after searching for 4—-5 hours was 10—15. Stran- 
gely enough I could never find it in any other locality than where 
I found it the first time. The vegetation was composed by ÅAcorus, 
Ranunculus lingua, Glyceria spectabilis, and Typha angustifolia. 
"I have no impression of the larva preferring any of these plants 
for the others; if so, it should probably be Acorus. In the aqua” 
ria the larva fastened itself to the most different plants and sat 
often for a fortnight or more fastened to the same spot. It was 
always restricted to very shallow water. I never found it deeper 
than !/3 meter. The best method to get the larvæ is to loosen 
the plants from the bottom with the roots and then to shake them 
