OF THE PHYTOZOA. 197 



engaging a gas (oxygen ?) under the influence of light. They exhale an evi- 

 dent spermatic odour. Their reproduction occurs by spontaneous division, 

 2-4 young ones being formed within the common integument. I have ob- 

 served the same mode of reproduction in the Euglem^, which act on the air 

 and tui^n to the light like DiseJmis, but have an extremely contractile body 

 changing its figure every moment, which will not admit of their being con- 

 founded with zoospores, and leaves no doubt of their animality. This binary 

 or quaternary division is met with also in the various species of TetmsporcBy 

 which, though arranged mth the Algae, appear to me of very doubtful vege- 

 table nature. In Tdraspora gelatinosa I have recognized green globules, dis- 

 posed in foiu's, and each furnished with two cilia of extreme length, which 

 are lost in the gelatinous mucus of which the frond of this supposed plant is 

 constituted. All these productions, as well as Gonium, Pandorina, Volvo.v, 

 Protococcus nivalis, &c., present, in my opinion, characters of animality 

 too decided and too permanent for it to be possible to refer them to the 

 vegetable kingdom ; and I think it would prove more convenient to 

 unite them, with aU the other Infusoria (Poh/gastrica) coloured green, in 

 one and the same group, which might be called CJilorozoidece. We have 

 before noticed the sweeping statement of M. Agassiz, that all the mouth- 

 less Infusoria are nothing but various forms and phases of development of 

 Algte." 



Although many natm-alists stoutly claim the Astasicea, and the genus Eu- 

 glena especially, as plants, yet others, and among them some of the most 

 able, particularly in Germany, stiLL pronounce them animals. But, as we 

 have before noticed, there are undoubted Euglena-iorms which are actually 

 phases of existence of known plants, and which, if watched, may be followed 

 in their development until by germination they assume all the special fea- 

 tures of those plants ; and, on the other hand, there are EuglencB which at no 

 period of their existence can be seen to germinate, although they may exhibit 

 a plant-like condition when encysted and motionless, like Protococcus resting- 

 cells. 



As an example of the former set of transitional beings, we may aj)peal to 

 the observations of Itzigsohn already recorded (p. 125), showing that, in the 

 development of Oscillatorice, minute Chlamydomonads are transformed into 

 Eagleme, that these in their turn generate microgonidia, which, after some in- 

 termediate transformations, eventually produce the ' Leptothrix,'' and lastly 

 the perfect OsciUatoria. Another illustration might be adduced from Cohn's 

 essay on Protococcus pluvialis, in which he points out both an Astasia- and a 

 Euglena-\SkQ phase of that unicellular plant. Let it, however, be noted that 

 whilst Cohn records a Ejiglena-yihdL^e in Protococcus, he nevertheless admits 

 the existence of animal Euglence, distinguished by their extraordinary con- 

 tractihty (Entiu. p. 208). Withal, this distinguished observer's discovery of 

 the mutual sexual relation of micro- and of macrogonidia constitutes (sup- 

 posing these reproductive products, as seems to be actually the case, to be 

 generated in EiiglencB) an additional argument for theii' vegetable natui^e, by 

 bringing them Tvithin the same category of organized beings as Volvox and 

 PaiKlorina. 



If Mr. Carter be correct in his account of Astasia, this genus can no longer 

 remain in the category of doubtful organisms, but must forthwith be trans- 

 ferred to the animal kingdom ;' for he asserts the existence of a mouth with 

 a complicated buccal apparatus for biting off and taking in food, of a strong 

 prehensile organ, and stomach-sacs. Besides, he speaks of its near affinity 

 mth Amoeba, and refers it to the Rhizopoda. In Euglena, on the contrary, no 

 mouth- or stomach-vesicles are discoverable, and the filament is comparatively 



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