168 Dr. G. 0. Wallich on the Ti/pe 



was announced in my " Further Observations on the Distinc- 

 tive Characters and Reproductive Phenomena of the Amoeban 

 Rhizopods," published in the ' Annals ' of Dec. 1863. And 

 at a still later period, when I had managed to establish 

 several colonies of healthy Gromice in my tanks, I had ample 

 opportunities of verifying my earlier observations in a suffi- 

 cient number of cases to render all further doubts on the 

 subject inadmissible. I may add that my examinations em- 

 braced both freshwater and marine forms of Gromia^ and that 

 no material distinction presented itself between the characters 

 of the two sets of specimens, beyond differences in size and 

 colour, or, I should rather say, in the presence or absence of 

 dirt on the otherwise nearly hyaline tests — the dirt being 

 generally present on the freshwater form, and as generally 

 absent on the saltwater one. After a time there was not the 

 slightest difficulty experienced in finding plenty of sufficiently 

 clean and hyaline tests to admit of the easy detection of the 

 two organs under notice. 



In the latest (1875) edition of ' The Microscope and its 

 Revelations,' Dr. Carpenter takes a first cautious step towards 

 a change of front, without, however, pointing out (as he might 

 with a very good grace have done) that his entire classification 

 was sapped to its foundations by the discovery that Groinia^ 

 whose pseudopodia he had declared to be precisely similar to 

 those of the lowest and simplest known form of Rhizopod, 

 possesses the two specialized organs which only make their 

 appearance '^ in the cases in which the differentiation into 

 ectosarc and endosarc has proceeded furthest." This omission 

 will perhaps explain itself on the publication, side by side, of 

 the two subjoined short extracts : — - 



1862. " Notliwitlistanding the 1875. " To the first of the orders 



apparently unrestricted polymor- thus marked out, the name Reti- 

 phism of the pseudopodial exten- cularia seems appropriate ; the 

 sions, it will be found that the second has been distinguished as 

 Rhizopods present three ve7-y di- Radiolaria; and the third may be 

 stinct types of pseudopodial confor- designated Lohosa. It must be 

 mntion, to one or other of which freely admitted, however, that 

 they may all be referred, and that these groups cannot be distinctly 

 all the groups are eminently marked out, the typical examples 

 natural" (Introd. Study Foram. which will now be described being 

 p_ 15,) connected by many intermediate 



forms. This is not to be wondered 

 at, when the extreme indefiniteness 

 which characterizes the lowest 

 type of animal life is duly borne in 

 mind." (The ' Microscope and its 

 Revelations,' 5th edit. p. 467.) 



