1883.] 



MICROSCOPICAL JOURNAL. 



89 



this country, and that those figured by 

 European naturalists which most nearly 

 approached it, lacked the symmetrical 

 shape of the enormous falchion crest, 

 and its singular characteristic curve. 

 ■ "hose most nearly approaching it in 

 he European species were Hyalo- 

 daphnia Kahlhcrgicnsis, and H. Cedcr- 

 strojnii, described by Schoedler in 

 Anhiv fiir Natiirgcschkhte, 1866. As 

 I have found no notice of this species 

 given by other observers up to this 

 time, it seems well to call attention to 

 it by publication of the sketch. As 

 the name of Daphnia Galcata has 

 already been appropiated, I have 

 provisionally called this D. kerusses. 

 J. D. C. 



Vibratile Cilia and ciliary 

 Motion. 



( Co.-:tinued from p :ge 75 ) 



Effect of Temperature Changes, 

 Electricity and Various Reagents 

 UPON Ciliary Motion. — In consider 

 ing the effects of changes in tempera- 

 ture, electricity, and various reagents 

 upon ciliary motion, I have en- 

 deavored to avoid a confusing mass of 

 details by tabulating the results of 

 numerous experiments, confining my- 

 self to a few general remarks. 



In general, the iimits of temperature 

 within which ciliary movement takes 

 place are from 0° to 45° C. Within 

 these boundaries the effect of increas- 

 ing the temperature is to hasten, of 

 lowering, to slow the movements. In 

 every case there is a certain tempera- 

 ture, — the optimum which, having 

 been reached, the movement seems to 

 continue indefinitely at the greatest 

 rapidity and with the highest energy. 

 This optimum is always some degrees 

 below the maximum ; if it be over- 

 stepped the motion becomes tempor- 

 arily exacerbated, failing after a time, 

 the sooner, the nearer the temperature 

 i'i to the maximum. While cessation 

 of movement takes place on the tem- 

 perature reaching the maximum (45° 

 C.) it may be revived if the temper- 



ature is not maintained too long, but 

 if the cell be warmed a few degrees 

 higher than the maximum, to the ultra- 

 maximum (about 48° C), death im- 

 mediately takes place. In this case 

 the cells become turbid through 

 coagulation of the albumen. The 

 effects of changes of temperature 

 on ciliary motion correspond very 

 well with the efifects of like changes 

 upon the movements of bacteria, as 

 established in the culture experiments 

 of Drs. Wood and Formad. * 



There seems to be no specific poi- 

 son for ciliary movement, excepting, 

 perhaps, in those cases in which it seems 

 to be under the influence of the will, 

 as when it serves for voluntary loco- 

 motion. Generally, however, there is 

 no direct influence of the toxic sub- 

 stance upon the cilia through the sub- 

 stance of the ciliated cell. 



Regarding the effects of electric 

 currents, we find great difference in 

 the various forms of ciliated cells. 

 Thus, the larger cilia belonging to the 

 branchial laminae of bivalves behave 

 towards electrical irritation much like 

 muscle, bending themselves with a 

 jerk, after an induction shock towards 

 the front, and remaining in this posi- 

 tion as in a cramp, the longer the 

 stronger the irritation. 



The thermic naUire of the influence 

 of the electric current is proven by 

 Engelmann, who shows that, with a 

 single exception, the rules governing 

 the effects of electricity upon vibratile 

 cilia are the same as with other elec- 

 trically irritable elements. 



Vibratile Cilia and Ciliary Mo- 

 tion IN the Vegetable Kingdom. — 

 The phenomena of ciliary motion as 

 exhibited in the animal kingdom are 

 familiar to every student of biology. 

 It is not so generally understood. 



* Micrococci multiply best at from 37^-40' 

 C. Higher temperatures up to 70° C. do not 

 destroy them, but only partially arrest their 

 multiplication which returns if ihe 70^ is 

 again reduced to 40^^ or 35.° 



Fungi, other than Micrococci, perish at a 

 temperature above 50° and proliferate well 

 only at 30° C, and below. 



