Introduction to Animal Morphology. 3 



sfyh\ A flagellum originates as a process from the 

 protoplasm mass, which first undulates, then becomes 

 globular, and finally elongates (Engelmann}. In the 

 formation of a row of cilia the undulating knob 

 elongates into a ridge, which splits into parallel bands, 

 rapidly changing into cilia. The rate of motion of 

 cilia varies per minute from 720* to 480 (Engelmann}, 

 190 (Krausc\ 150-100 (Valentin}. 



The effects of reagents on protoplasmic motions are as 

 follows: i. Very weak alcohol, moderate heat,f and very 

 diluted alkalies favour motions of the 2nd and 3rd form. 

 2. Ether, strong alcohol, chloroform, stop motions and render 

 the mass granular. 3. Hydrocyanic acid arrests movements. 

 4. Vegetable alkaloids, as a rule, affect them but little. 5. Weak 

 acetic acid causes irregular contractions, and finally checks 

 motion. 6. Fresh water makes protoplasm masses spherical 

 and develops the first form of motion.f 7- Carbonic acid de- 

 stroys ciliary action (Kiihne}, but the access of air, if resorted 

 to speedily, restores it. 8. Hydrogen checks ciliary action, 

 but cilia thus stopped, if soon exposed to carbonic anhydride, 

 are at first set in motion, and then finally stop (Engelmann}. 

 9. Cold checks amoeboid motion and rotation of the yelk- 

 spheres, but (if not excessive) only retards, but does not 

 arrest, growth or life-progress. 10. Weak induction currents 

 accelerate amoeboid motions or produce contraction (Kiihne, 

 Golubew} ; they also accelerate ciliary action (Kistiakewsky). 

 Every variation of intensity of the current acts as an excitant, 

 producing alternate contractions and relaxations. The 

 closure of a constant current is a stronger stimulus than the 

 opening. Strong currents stop all motions (Engelmann}. 



I observed this rate in Planaria. 



t M .t accelerates the motions of cilia (TTWvr), and the loco- 



motion of corpuscle, which is greatest at ioo 13 F. (Schultzc). Yelk 

 masses contract and dilate at 90 1 . chko). 1 13 F. coagulates 







t The spherical state may be strong contraction (fCuhnc) 



