Observations on British Zoophytes and Protozoa. 157 



In citing these instances, I do not mean to infer that 

 electricity is engaged in the vital movements of the sarcode, 

 but merely to show how movements resembling them can 

 be closely imitated by processes connected with inorganic 

 matters, the rationale of which we have no difficulty in ex- 

 plaining. 



Reproduction. — In a former paper read before this Society, 

 I communicated the discovery of true ova, with germinal 

 vesicle and spot, in a rhizopod Truncatalina, and considered 

 that, as it was impossible that bodies of so great a size could 

 escape from the openings of the shell, it was probable that 

 in these genera a " polymorphic development took place, 

 similar to that described by Carter in Amoeha verrucosa, and 

 such also as seems to occur in Gregarina, either with or 

 without a previous process of conjugation. In Boderia 

 such a development plainly occurs. In specimens under 

 observation these nuclei or ova were seen to disappear ; and 

 some hours afterwards the sarcode of the animal burst 

 or issued from its envelope, and spread itself in ragged 

 masses (fig. 3) over the glass, connected by drawn-out threads. 

 In the course of a few hours later the sarcode became entirely 

 dissipated, leaving a swarm of naviculoid bodies (fig. 4) 

 attached to the glass, from each of which, in a day or two, 

 issued a minute nucleated and amoeboid mass (fig. 7) of sar- 

 code. These little amoebas existed for many weeks as a 

 closely aggregated band of many inches in length near the 

 surface of the water, without assuming a test, or putting 

 forth pseudopodia ; nor were the latter processes ever ob- 

 served, although minute specimens gradually made their 

 appearance in the vessel in considerable numbers. I am 

 disposed to think that the change from the naked amoeboid 

 to the incysted rhizopodic form in this animal constitutes a 

 distinct stage in its development. We here have the life 

 history of the Ehizopoda and Gregarinidse brought in very 

 close analogy to each other : — Thus, in Gregarina we have a 

 conjugating process, followed by an encysting of the animals, 

 or the encysting may take place in a single Gregarina ; 

 next, " certain globular vesicles appear in the cyst, and these 

 become metamorphosed into ' pseudo-navicula?/" The cyst 



