Mr. H. J. Carter on the Organization of Infusoria. 359 



the nucleus of the vegetable cell, but subsequently it takes on this, 

 apparently, generative function. 



Ovules. — These are discoid, nucleated cells in Spongilla and 

 Amcehuy but globular in the other freshwater Rhizopoda. The 

 author first pointed out their nature and development in Spongilla 

 in 1848, and a repetition of the experiments which led to this con- 

 clusion has been followed by the same results. In Spongilla they 

 are contained in globular transparent vesicles in the seed-like body 

 or capsule, and each of these globular vesicles, at an early period, 

 has been found to possess all the characters of an Amoeba in the 

 same condition about to become capsuled; so that the seed-like 

 bodies of Spongilla are but an aggregation of ova-bearing sponge- 

 cells, enclosed under one common covering. In Euglypha the ovules 

 are globular, and appear around the capsule of the nucleus, not 

 inside it. At an early period, in Spongilla and Amoeba^ the ovule 

 consists of a discoid, transparent capsule, lined with a film of semi- 

 transparent matter, presenting a glairy, faint greenish-yellow colour ; 

 the latter afterwards becomes more opake and defined, and subse- 

 quently, in the course of development, may present a central pellucid 

 circular area, in the midst of which is a minute, faint yellow body ; 

 the sarcode then becomes developed, its granules appear, and the 

 ovule becomes more or less polymorphic, while the central body of 

 the pellucid area seems to originate the nucleus. Such are the 

 changes observed in the development of the ovule of the freshwater 

 Rhizopoda. Similar ovules also occur in Astasia and in Euglena. 

 When the capsule of the nucleus has been present in an Amoeba 

 filled with ovules far advanced, it has appeared enlarged, and the 

 nucleus hardly perceptible or effete. 



Spermatozoids 1 — This term is applied provisionally to the granules 

 developed from the nucleus, for it not only would appear that in 

 Spongilla^ Amoeba and Euglypha this development frequently occurs 

 without the most distant sign of the presence of ovules, but in Eu- 

 glypha it is seen to occur both separate and together ; that is, the 

 granular development is sometimes present when the ovules (all of 

 the same size and five times the diameter of the granules) are also 

 present around the capsule of the nucleus ; so that if the granules 

 passed into ovules, the latter might be expected to be present of 

 different sizes, which in fact is the case in Spongilla and Amoeba. 



Impregnation. — Although the congress of two individuals in 

 Amoeba and Euglypha has frequently been seen by the author, yet it 

 is not uncommon to witness three and sometimes four of the latter 

 adhering together by the heads; and whatever bearing this may 

 have on generation, the ovules and granular development of the nu- 

 cleus are not preparatory to this act in Euglypha, but subsequent to 

 it. Should these granules hereafter be found to have a fertilizing 

 influence over the ovules, the process may be extended even to Cla- 

 dophora among the filamentous Algse, which, consisting merely of a 

 layer of nucleated cells within one large cell, would not appear to 

 require any more organs for reproduction than these cells themselves 

 possess ; and among the Diatomeee and Desmidiese and filamentous 

 Algae, such granules presenting a motion distinct from that of the 



