146 Dr. G. C. Wallich on the Value of 



of this system in the sarcode of Amoeba not only seem to 

 burst into each other and into the vesicula," is not only alto- 

 gether irreconcilable with the facts advanced regarding the 

 "complete isolation of the contractile vesicle and its supple- 

 mentary cavities from the body and from each other/' but irre- 

 concilable with any other view than that the orifices of dis- 

 charge are extemporized, and not permanent portions of the 

 structure. 



But we have some clue to the process by which the discharge 

 of the contractile vesicle is supposed to be effected, according to 

 Mr. Carter, from an observation made by him in the ' Annals ' 

 for 1856 (vol. xviii. p. 131), namely, that " in Amoeba it [the 

 contractile vesicle] is attached to the pellicula, and therefore no 

 sarcode exists immediately opposite this point." Here, again, 

 we find no mention of what is now described as taking place in 

 A. princeps ; for the remark is illustrated, not by any reference 

 to that form, but to A. radiosa — no] allusion being made to any 

 fixed point of discharge or, indeed, any determinate aspects of 

 the body, but it beiug simply stated that the figure appended 

 " presents a mammilliform projection preparatory to discharging 

 its contents." 



Reverting now to the number of contractile vesicles, it will be 

 seen that Mr. Carter expresses himself with perplexing ambi- 

 guity, as the subjoined extracts testify : — 



" In Amceba a.ndActinophryst\ie vesicula is generally single ; sometimes 

 there are two, and not unfrequently in larger Amoebee a greater number " 

 ('Annals,' 2nd ser. vol. xviii. p. 128). 



" There is no knowing how many vesiculae there may be in Amceba ; 

 while Actinophrys Sol (Ehr.) is surrounded by a jjeripheral layer of vesi- 

 cles, which, when fully dilated, appear to be all of the same size, to have 

 the power of commimicating with each other, and each individually to 

 contract and discharge its contents externally as occasion may require ; 

 though, generally, one only appears and disappears in the same place " 

 {loc. cit., succeeding page). 



" In A. princeps the normal number is one ; but there are many smaller 

 ones which act as sinuses around it, and one of these occasionally becomes 

 so enlarged as to look like a second vesicula, yet it also ultimately dis- 

 charges its contents into the main one. Where the vesicula discharges 

 itself, it again recommences to appear; and there, also, the accessory 

 sinuses may be best seen as they successively become dilated and discharge 

 their contents into the vesicula " (' Annals,' July 1863, p. 38), 



The condition of abnormal vacuolation referred to by me (in 

 the * Annals ' for June, p. 436) as presaging disruption and 

 death, is probably the same as that described by Mr. Carter as 

 " an intense vacuolar state of the sarcode, which makes it look 

 like an areolar tissue composed of vesicles, diminishing to a 

 smallness that cannot be determined by the microscope." But 

 he adds, " whether this state be a part of the vesicular system, or 



