66 EDWIN S. GOODRICH. 
evaporation the solution leaves a film of transparent substance 
without crystallisation. Boiled with caustic potash and cupric 
sulphate we get no reduction. ‘The solution answers to a 
certain exteut to the proteid tests, turning straw-coloured 
with the xanthoproteic test, and pale lilac with the biuret 
test. Boiling with Millon’s reagent produces no more than a 
pinkish hue. Tannic acid in the solution acidified with acetic 
acid gives a white precipitate.’ Sodium sulphate and po- 
tassium ferrocyanide give no precipitate. If we treat the 
solution with absolute alcohol we get a white precipitate, and 
the filtered liquid answers no more to the above tests. 
The Chete.—It is generally assumed that the cheetz are 
chitinous, but this seems to be by no means always the case. The 
cheetee of Vermiculus and Enchytreeus are insoluble in distilled 
water (hot or cold), alcohol, ether, caustic potash (even boiling), 
acetic and oxalic acids, hydrochloric acid (even after prolonged 
boiling for some minutes). In strong sulphuric acid they 
become swollen and soft, finally dissolving on heating. 
The cheetz of the earthworm are insoluble in distilled water, 
alcohol, ether, caustic potash, lime water, acetic and oxalic 
acids; soluble in strong hot sulphuric acid. Boiled in strong 
caustic potash the chete become somewhat swollen and broken 
up, but do not dissolve. If they be now washed and placed in 
concentrated hydrochloric acid the proximal region (that part 
which lies in the body-wall) is rapidly dissolved, partially in 
the largest cheetz, and almost entirely in the smaller. If the 
acid be now boiled the resisting distal region is soon dissolved, 
leaving only a thin colourless layer which formed a sort of 
cap over the cheta. This shell appears to be insoluble in 
hydrochloric acid like the entire cheta in Vermiculus. The 
chetz of Vermiculus, Enchytreeus, and Lumbricus become 
orange with xanthoproteic test, and crimson with Millon’s 
test. 
Below are set forth in tabular form the chief of these 
results : 
1 It behaves, in fact, somewhat like a peptone. 
