the Distinctive Characters in Amoeba. 137 



is not invested, as lie supposes the rest of the body to be, with 

 the " pelUcula," which I imagine is not the case, from what 

 he says in the 'Annals' for July 1863. In that paper, at 

 page 31, he says the " pseudopodia proceed from q, posterior end 

 which is normally capped with a tuft of villous prolongations.'' 

 It will be seen that this expression admits of two diametrically 

 opposite interpretations ; that is to say, it may either mean that 

 the pseudopodia are projected //'o??? (in the sense of the opposite 

 direction to) the villous appendage, or that they are actually 

 projected from the midst of the villi themselves. If we accept 

 the first interpretation, it is evident that Mr. Carter, when de- 

 scribing the characters of Amoeba generally, in 1856, must have 

 been unaware of the true significance of the villous appendage ; 

 for he referred to Amoeba Gleichenii, and not A. jjrinceps, in order 

 to exemplify the prehensile organ of the genus. In doing so, 

 moreover, he says, " To what portion of the body of the Amoeba 

 the pedicular process corresponds I am ignorant. But it is in- 

 teresting to see that, in Euglena, lohere a similar process takes 

 place, it is the antei'ior extremity which is next the pedicle'' — 

 that is to say, the opposite extremity to that in which it occurs in 

 A. villosa or A.princeps. 



On the other hand, if we accept the second interpretation, as 

 already pointed out, it is altogether irreconcilable with the 

 appearances presented, which may be seen at a glance on exami- 

 nation of ever-y form exhibiting the villous appendage. 



I have seen no reason to call in question the generally re- 

 ceived opinion that, after each contraction, the contractile vesicle 

 reappears at the point of obliteration, or in immediate contact 

 with that point. Alluding to this fact, Mr. Carter (in the 

 'Annals' for 1856, vol. xviii. p. 128) says, "We may perhaps 

 infer that the situation of the vesicula in Amoeba and Actino- 

 phrys also is fixed, though, from their incessant polymorphism, 

 it appears to be continually varying in position." In the case 

 of Amoeba villosa, however, the polymorphism does not interfere 

 with observation ; and hence it becomes manifest, at a glance, 

 that the contractile vesicle reappears as above stated — the villous 

 organ, in the midst, or at the margin, of which the contraction 

 invariably takes place, afibrding a fixed point for comparison. 

 In Actinophrys Eichhornii, again, when examined on a slide under 

 a thin glass cover, there is no difficulty in obtaining a tangential 

 position of the contractile vesicle at the same time that the body 

 of the creature is kept immoveable ; and we thus obtain a per- 

 fect view of the alternating action. But in the latter species I 

 have never detected anything like supplementary vesicles given 

 off from the primary one, or any appearance indicating that the 



