mountains, concluded that the beetle had carried the alge. Later he ex- 
amined six beetles belonging to three species, from five different habitats 
and found attached to them twenty-three species of alge. 
These ciliates and alge, however, were attached to beetles in the water. 
When the beetles leave the water these attached organisms are suddenly 
transferred from an aquatic to an eerial environment. This new enyiron- 
ment differs from the old one in temperature and humidity. How long 
these organisms can resist these changed conditions and how long the 
beetles stay out of water are facts that must be known before the role of 
insects in the distribution of attached organisms can be accurately deter- 
mined. ‘The fact that aquatic beetles fly at night reduces the harmful effect 
of evaporation. Experiments are planned to selve these problems, 
In the notes on Epistylis, I have indicated that that species of this 
genus ean remain out of water for some time without fatal results. The 
colony 1eferred to remained on a slide under cover in a room with low 
relative humidity for more thau fifteen hours without it being fatal to all 
of the zooids. While a colony of this species attached to the thorax of a 
beetle making a nocturnal migratory flight would not have the protection 
against evaporation of the two glass plates, this would be compensated 
in some degree by the more humid and cooler night air. 
That wind is responsible for the distribution of many protozoa and 
rotifers is 2 fact which is familiar to any one who has eyer made a hay 
infusion. The presence of these organisms and of tardigrada in the pond, 
is probably due to wind distribution. Just how far an organism can be 
transported by win@ depends upon the size and specific gravity of its spores. 
eggs or cysts, and upon its power to resist drying, extreme temperature. 
etc. These facts are, in a large number cf cases, unknown. 
Cysts of Euglena are common in almost every culture, but it does not 
follow that this is the form in which they are wind-blown. Assuming a 
constant specific gravity, it is certain that the buoyancy of a cyst increases 
as the reciprocal of its diameter. As an adaptation to this law, many 
organisms form extremely minute spores. 
It is rendered very probable by Calkins (07) that in Amaba proteus 
yery minute spores are formed. From his figures I have determined the 
diameter of the teriiary nuclei (which with a bit of cytoplasm are pre- 
sumed to form the spore). to be 1 ~ or less. Comparing these spore nuclei 
in Calkins ('07), Fig. 14, with the amceba figured in his earlier papers, 
