384 The American Naturalist. [^lay, 
served a great many black ants traveling out upon the willow 
twigs, and a few of them apparently entangled upon the sur- 
face of the mass which was falling to pieces. With some diffi- 
culty and with the help of a coolie, I succeeded in drawing the 
most perfect of these objects within reach, and by cutting the 
willow branches getting it entire to the ground. 
I was quite confident that it was of insect origin and my 
curiosity to ascertain its nature and structure was great. I 
asked the coolie what it was. His reply was the usual " Wak- 
arimasen," Anglice "don't know." The outer surface was 
dry and had the appearance of very thin brown wafer. At 
the places where the willow twigs passed in and out of the 
mass there were projecting points and at the apices of these 
in several instances there was an exudation of glairy mat- 
ter, which had the. appearance of very fine soap suds. All 
over the exterior were the bodies and wings of small insects 
which had evidently been entrapped in the mass when it had 
been soft. A few ants and flies were struggling in the bubbly, 
vesicular scum, which was freshest near one or two of the 
branches at their insertion into the mass, as I have described. 
Taking my pocket knife 1 opened the curious structure and 
found its interior to be composed of a mass of tough, glairy, 
froth, resembling the white of an egg that has been well beaten, 
but of a dirty, yellowish brown color. What, however, was 
my amazement to find scattered through it, and wriggling about 
hither and thither, a colony of tadpoles, of which I counted 
twenty-two. They were black in color with white bellies, 
exceedingly lively, and apparently, very much at home. Here 
and there in the mass were the remains of insects, principally 
legs and wings and the chitinous outer coverings of the abdom- 
inal and thoracic segments of black ants. 
Having no means of preserving the tadpoles with me, as I 
had hastily gone to Nikko with Professor Todd, leaving my 
alcohol behind me at Tokio, I resolved to let the best of the 
remaining two nests remain until the morning of the 22d, 
when I resolved to secure it, and if possible take it with me to 
Tokio. I however took down the largest of the two remain- 
