OF THE PHYTOZOA. 127 



transverse diameters, and is so slow as to amount at the utmost to no more 

 than 1-40'" per minute. The form of the body resembles that of Amoeba 

 princeiis (Ehrenberg). The vesicle in the hinder part of the body, which 

 was fii'st described by Ehrenberg as a mouth, and afterwards as an ovarium, 

 is also present. 



"^ After four or five days the Amoeba assumes a spherical shape and becomes 

 motionless, the vesicular body expanding and contracting rapidly as before, 

 in a manner similar to what takes place in many Vorticellce. These spherical 

 motionless Amoebce are then for the most part united by a mucilage into 

 groups of from ten to twenty. The mucilage appears to be produced by the 

 decomposition of a cast-off external skin. 



" In about a fortnight after the commencement of the experiment, a green 

 point appears in the interior of the spherical colourless body of the Amoeba ; 

 this point gradually increases in size until it fills up the entu-e hollow of the 

 Amoeba, and after becoming covered with a cuticle it escapes in the form of 

 an elliptical bright green cell, 1-300'" in diameter, resembhng a Protococcus. 

 It exhibits a round transparent cavity, devoid of chlorophyll, corresponding 

 in size and position to the vesicular body of the Amoeba, and resembling at 

 its coloiu'less apex the motile gonidia of Cladajjliora. A few days later the 

 elliptic or roundish cell lengthens, a fonnation of transverse septa commences, 

 and the unicellular Alga becomes an articulated one. 



" All these transformations of Phytozoa into SpirUla, Vibriones, Monads, 

 Amoebce, unicellular and articulated Algse, may be observed not only in the 

 detached Phytozoa, but in those wliich remain in the interior of the sections 

 of the antheridia. In those antheridia of which the Phytozoa are not fully 

 ripe, the Amoebce are seen to originate in the middle of the internal mass of 

 phytozoary cells : some of them make their way out through the softened 

 mass of cellular tissue ; but others remain in the interior of the antheridium 

 until their development into an articulated Alga. 



" Contemporaneously with Amoeba, and often earlier, there may be seen, 

 amidst the mass of Monads, bodies very similar in form and motion to the 

 genus Boclo (socicdis), and which increase by transverse division ; they have 

 the front end fm-nished with a long whip-shaped antenna or cihum similar 

 to that of Euglena. At their fii^st appearance, their motion, their change of 

 form, and their whole exterior differ so Kttle from the earhest states of 

 Amoeba, that at this period they cannot be distinguished. In these early 

 stages they both resemble CJdamydomonas destruens of Ehrenberg. 



" The above forms imiformly make their appearance, and always in the 

 succession above described. It is true that other forms, such as Uvellce and 

 even Lejotomitce and Periconice, are sometimes met with, the germs of which 

 may have been imported by the atmosphere dming the observation ; but these 

 organisms, ivliich cdivaijs appear singly and after the commencement of the 

 observation, do not interfere with the above results when we consider the 

 immense number of the Phytozoa and their uniform and contemporaneous 

 transformations. If about a dozen preparations are made, and if they are 

 carefully covered with a bell-glass after each observation, and if care be 

 taken not to extend the observations for too long a time at once, at least half 

 of the preparations -will be free from all admixture of foreign organisms." 



Itr. Carter has advanced some remarkable statements respecting the de- 

 velopment of Amoebifonn and other Infusoria from the so-called ' gonidial 

 ceUs ' of the mucous contents of various Algae — as Chara, NiteUa, Clado- 

 phora, Spirogyra, and Hydrodictyon, and also of some Desmidieae and Eu- 

 glenece (A. N. H. 1856, xvii. p. 101). Again, he finds (p. 114) the cells of 

 Spirogyroi particularly infested, during conjugation, with EugJence, which are 



