134 Dr. G. C. Wallicli on the Value of 



now says, " At first they are delicate, and their capsules so unde- 

 veloped that they present the appearance of cells composed of 

 nothing but a fine, delicate, semitransparent, homogeneous 

 plasma; but as they grow older, this becomes granuliferous, 

 and towards the adult state there is a distinct capsule," it being 

 stated that they are the produce of the repeated binary division 

 of the parent nucleus. 



On the last-named head I cannot speak with certainty, but 

 several reasons have led me provisionally to adopt a somewhat 

 different view. Two of these may be mentioned more particu- 

 larly. Mr. Carter says, "Of course, when present [viz. the 

 ovules], there is no nucleus to be seen with them.'" (Annals, 

 July 1863, p. 41.) Now, I can confidently assert that in spe- 

 cimens of A. villosa, charged with quite as large a number of 

 these bodies as are described as having been counted by him in 

 a specimen of A. princeps, the nucleus was present also ; whilst 

 in such as showed fewer sarcoblasts I constantly met with two, 

 and now and then three, distinct nuclei, of almost equal size. 

 And, again, in those individuals which contained sarcoblasts, 

 the nuclei, whether single or multiple, were invariably less 

 granular than those without them, the hyaline ring observable 

 between the inner surface of the nuclear capsule and the nucleus 

 itself of the latter specimens being more or less completely obli- 

 terated. But to this question I shall recur again presently. 



From the description given of these bodies, now called " re- 

 productive cells " by Mr. Carter, and which has appeared since 

 my last paper was published, it is evident that I was in error 

 when I stated my belief that the nucleated corpuscles of Amosba 

 villosa (in contradistinction to the non-nucleated sarcoblasts) 

 were probably identical with the " reproductive cells " oi A. 

 princeps (Carter). But inasmuch as I was ignorant, at the time 

 my paper was written, that he had changed his view regarding 

 the constitution of these bodies since the date of his previously 

 published observations (1856 & 1857), it will be seen I had no 

 alternative but to assume that, out of two kinds of corpuscles, 

 differing from each other chiefly in the one being nucleated, the 

 other devoid of nucleus, the kind presenting a nucleus corre- 

 ^onded with the " ovules " which up to that period stood de- 

 sci'ibed by him as possessing a similar feature. 



I am glad to find, however, that the detection of this error, 

 unavoidable as it was on my part, causes Mr. Carter's and my 

 views regarding the reproductive office of his "reproductive 

 cells " and my sarcoblasts to coincide in a great measure, al- 

 though I am unable to confirm, by my own observation, the 

 opinion entertained by him as to their being surrounded by a 

 distinct membrane. But I cannot speak positively on the point 



