RKPRODUC'J'ION OF RHIZOPODA. Sf) 



that it has any relation to the act of reproduction. Certain it is that such a ''zygosis" may 

 occur, not between two only, but between several individuals at once, their number being 

 recognised by that of their contractile vesicles ; and that after remaining thus coherent for 

 several hours, they may separate again without having undergone any discoverable change. 

 Whether, by any process of a sexual character, germs are developed within the body, and 

 are then set free, must at present be regarded as quite uncertain ; the only reliable evidence 

 on this point being that which is afforded by the observation of Professor KiJlliker, that very 

 small individuals oi Jcfi//op/tr//s sometimes present themselves, measuring no more than -01 or 

 "02 millim. (l-2560th or l-12S0th incli), and presenting very few and inconspicuous granules. 

 But these may be gemmae or small segments separated by the process of subdivision, and not 

 sexual products. And it must for the present be held to be quite uncertain, whether the 

 body wliicli we know as Aciinoplirijs does not go through some entirely different phase, before 

 the completion of its life-history. — A like process of conjugation has been seen to take place 

 also in several AinmhiiKE, testaceous as well as naked ; and the same doubt exists whether 

 this " conjugation '' has any import at all corresponding to that of sexual union among the 

 higher animals, and whether the being which is known as Amceba is anything more than one 

 form of an organism, whicli would present itself to us under other very diverse aspects if the 

 whole of its life-history were known to us.* 



44. Certain appearances, however, have been obsei-ved by Mr. H. J. Carter (xxii, 

 pp. 223-233) among Amahina and Actinophnjna, which may be provisionally accepted as 

 indicating that true sexual products are formed in the interior of their bodies, and arc after- 

 wards set free by their disintegration. In Amaba the formation of the male apparatus appears 

 to commence by an increase of size in the vesicular portion of the nucleus, which also becomes 

 more or less globular (Plate IV, fig. 6, a) ; and its contained aggregation of granules then aug- 

 ments so as to occupy a third of the interior of the animalcule, and undergoes successive 

 binary subdivisions, by which it is broken up into numerous segments. These segments 

 assume a circular compressed or globular form, and continue entire until the granules 

 (spermatozoids ?) of which they are composed become fully developed, when the latter 

 acquire the power of locomotion, and then separate from each other, the original containing 

 vesicle in the meanwhile disappearing. In this way some individuals out of a group of 

 Amceba radiosa bearing such granules were seen moving about, even when so reduced that 

 hardly anything but their external pellicle and the one or two spherical segments of the 

 granulated nucleus that remained in their interior were left. Sometimes these segments 

 are evidently held together by a soft mucous envelope, which, being polymorphic, assumes 

 the form of Actimphriis (fig. 7), and exhibits locomotive power ; while in other instances tliis 

 capsule becomes firm, transparent, and spherical ; and the granules do not leave it until 

 they become endowed with independent activity. When the latter is the case, the sperma- 



* The Author considers that it would be foreigu to tlic purpose of the present work, were lie here to 

 entur upon a discussion of the curious observations of Hartig, Carter, and others, who maintain tliat 

 Amceba and Actinophrijs, or organisms undistinguishable from them, are formed as individualised seg- 

 ments of protoplasm within Vegetable cells, entering upon their independent Animal life when set free 

 from these. 



