138 
Bulletin Wisconsin Natural History Society. [Vol. 10, Nos. 3-4. 
“bloom "Cladophora appears and covers the littoral rocks with a 
thick mat of green.” 
The summer of 1910 was another marked season of the bloom, 
Clathrocystis being especially abundant. The lake was quite low 
and the rocky beach had masses of drying green scum, turned 
brown on the higher sun-scorched stones, still greenish nearer the 
water. The lake itself looked for more than a (mile out like 
a sea of green paint. Is there any ground for the belief that the 
food supply has something to do with the green voidings of the 
adult? Cases among the insects are known where voidings are 
colored by the food eaten just as certainly as examples where the 
voidings differ in color from the food eaten. And it is also known 
that voidings may be green from other causes than the presence 
of chlorophyll. Thus the question may be dismissed as one for 
theoretical curiosity only, were it not for the practical need of 
ascertaining the food supply of the larva in tracing the life history 
of any insect, and also the economic nuisance made by the colored 
droppings. I therefore attempt a review of the literature dealing 
with the Chironomid larvae. 
Larval Food and Habits vs. Green Specks Made by Adults .— 
Papers on the internal anatomy of midge forms seem to throw no 
light on the question of excreta colors, a question primarily con- 
cerned with the nuisance of the adults. The only internal anatomy 
studying the alimentary canal of the species, seems to be by 
Vignon (1899, 1596-8) although Balbiani (1881) and Korschalt 
(1884) studied the salivary glands, and Folsom (1909, 91) shows 
the nervous system from Brandt (1879, iot), and Meinert (1886, 
438) some other details of structure. But these authors fail to 
elucidate the query. Long before this, the metamorphosis of 
plumosus seems to have been worked out by Schubaert (1849, 
1850, 1854), but remains, in the language of Holland, buried to 
most authors. Anatomical papers on the family in general are not 
cited in particular although reference must be made to them as 
they treat frequently of species which were not identified, and, on 
the other hand, detail structures that must hold for the whole sub¬ 
family. Thus the embroyology of C. nigro-zdridis Macq. has been 
worked out by Dr. Weismann (1864,3) with 101 figures on seven 
copper plates, and Jaworowski (1882), and Kupffer (1866 and 
1867) ; this species studied being the one to reveal paedogenesis 
