536 SYSTEMATIC niSTORY OF THE INFUSOEIA. 



from spermatozoa, have indeed lost their life in Fritzsche's tinctiu'e of iodine, 

 since their evidently purely physical molecular movement remained un- 

 destroyed. 



''.... Fritzsche has completely settled the matter ; and every unprejudiced 

 observer may convince himself with ease of the completely untenable natui'e 

 of the wonders formerly spun out, especially by Meyen. The confirmatory 

 observations of Nageli on this point are also of great value." 



Again, he says — '' As to the mechanism of the motion, we know just as little 

 as we do of that of the moving cilia ; of the cause of motion, of the motive 

 power, just as much as of that of the contraction of the primitive muscular 

 fibre, of the motion of animal spermatic filaments, and of the vibratile ciUa 

 on animal and vegetable cells ; that is to say, absolutely nothing." 



Fui'ther, in reference to the motion of the so-called spermatozoa, Schleiden 

 observes — ^' There can be no question as to its not being a vital phenomenon, 

 because the motions continue even in the alcoholic tincture of iodine (an 

 absolute poison for all vegetable and animal life), of which one may readily 

 convince himself, and which Fritzsche has, with his well-known accuracy, 

 shown to be the case in a great number of plants." (Dr. Lankester's trans- 

 lation, pp. 99 and 359.) This assertion of Schleiden, that tincture of iodine 

 is an absolute poison to all animal and vegetable life, must be received with 

 reserve, since animalcular life has been known to exist in agents, such as 

 strong acids and mineral poisons, which, a priori, would appear quite as 

 inimical to it as tincture of iodine ; and even minute animals — the Acari, of 

 far higher organization than the Polygastrica, have been stated to presei-ve 

 life in strong acetic acid. 



Before dismissing this subject, it may be useful to append some observa- 

 tions made by Wagner and Leuckart, in their elaborate and original article 

 before-quoted. 



Having stated that, up to the most recent period, the so-named spermatozoa 

 of animals have been considered independent animal organisms, or parasitical 

 animals, and classed among the Infusoria, the authors proceed to say that 

 such assumption is perfectly irreconcileable with our present knowledge of 

 these bodies, derived principally from the discoveries of R. Wagner, Von 

 Siebold, and Kolliker : — " With our existing means of scientific diagnosis it 

 can be proved that the formations in question are mere elementary consti- 

 tuents of the animal organization, like the ova — constituents equally as neces- 

 sary for the spermatic fiuid as the blood-globules are for the blood. The re- 

 markable phenomena of the life of spermatozoa are quite analogous to those 

 phenomena of motion observable not only in animal formations, but also in 

 vegetable structures — as, for instance, in the spores of Algae and of the lower 

 species of Fungi, and in the so -termed Vihriones which grow out into the fibres 

 of the Conferva called Hygrocrocis. Moreover, an unprejudiced observation \d\\ 

 prove that the spermatozoa are eveiywhere void of a special organization, and 

 consist of an uniform homogeneous substance, which exhibits, when examined 

 by the microscope, a yellow amber-like ghtter. The opinion of an internal 

 organization of the developed animal elements was not a little supported by 

 the various remarkable phenomena of motion which were frequently perceived 

 in them. In former times, when people had no idea of the existence and 

 extent of the so-called automatic phenomena of motions which take place 

 without the intervention or influence of the nervous system — when nothing 

 was known of the motion very similar to a voluntary one which exists even 

 in plants — this movement was certainly calculated to place the independent 

 animal nature of the spermatozoa beyond a doubt. But it is different now. 

 We know that motion is not an exclusive atti'ibute of animals, and that an 



