IO CHARLES E. BILLS. 



By appropriate concentrations of propyl alcohol other micro- 

 scopic animals can be narcotized, though with less advantage than 

 Paramccium. Paramecinin bursaria is paralyzed, but cyclosis also 

 is stopped. The erratic movements of O.vytricha continue, though 

 less frequently and energetically. Spirostomum gives acute avoid- 

 ing reactions, twisting and bending so sharply at the peristome that 

 the body is frequently severed. The cilia on the fragments con- 

 tinue to beat as long as any ectoplasm remains, but those on un- 

 broken animals that are narcotized quickly disappear. S tent or 

 becomes quiet, and some of the cilia at either extremity continue 

 to beat; it contracts so much, however, that little can be seen 

 within. Colpidium and Colpoda become quiet, but the internal 

 activities also cease. The contractile flagellates Euglcna, Pcra- 

 nciiia and Distigina are stimulated to pronounced euglenoid con- 

 tortions ; their flagella are frequently lost, and may be grown again 

 in fresh media. In the case of Perancma the writer has observed 

 the flagellum actually regenerate about one fifth its length in three 

 hours. Of the rotifers, Monostyla narcotizes satisfactorily; many 

 of the others, however, merely undergo contortions up to the point 

 of death. The various larvae and nematodes that were observed 

 gave likewise results of no special interest. In general, then, it 

 may be said that while propyl alcohol gives a more or less effective 

 narcotization in a number of microorganisms, Paramccium is the 

 only form studied in which internal activities of a strikingly ob- 

 vious character obtained after narcotization. 



Some paramecia, narcotized in accordance with the technique 

 above indicated, were examined in detail. It was ascertained that 

 narcotization greatly simplifies the study of familiar details 

 cyclosis, functioning of the vacuoles, structure and activities of the 

 cesophagus, and feeding. Several new observations and correc- 

 tions were made ; these are indicated below with the topics to 

 which they refer. 



In a narcotized paramecium, lying with the oral groove up, and 

 the anterior end pointing to " twelve o'clock," there can be seen a 

 steady and vigorous cyclosis extending anteriorly along the right 

 fold of the body (anterior stream) and posteriorly along the left 

 fold (posterior stream). The writer noticed that the cyclosis may 



