51.6 
REVIEWS. 
nacktfiissigen Zweige der Charen,” which may be anglicized tlius— 
“ On the proembryos and the barefooted shoots of the Oharse.” We 
feel rather inclined to take exception to the use of the word “ nackt- 
fiissigen,” for when the organs in question come to be described, it 
would seem that “ nacktbeinige” (or whatever may be the proper 
German word for “bar elegged”) would be more applicable than the 
word “ nacktfdssigebut these remarks might be objected to as 
hypercritical. 
With regard to the word “ Yorkeim,” or “pro-embryo,” we con¬ 
sider it decidedly objectionable. The new plant (as will be seen 
from what follows) is produced by gemmation, and not from an em¬ 
bryo. In fact, the embryology in Chara is at present quite obscure. 
It is known that the so-called globules (or antheridia) contain sper¬ 
matozoa, and it is suspected that the latter obtain access to the 
central cell of the nucule, and impregnate it; but the process of im¬ 
pregnation has not been observed, nor is there known to be any alter¬ 
nation of generation, as in Terns and Equisetacese. To speak of 
the “ pro-embryo” of a plant, in which nothing answering to an 
embryo is known, is certainly a misnomer. # Tor the purposes of this 
paper, however, we must continue to use the word, subject to the 
above protest. 
It is well known that in the Mosses and Liverworts the so-called 
proembryo is a confervoid process, which precedes the formation of a 
* Dr. Hofmeister, in his work on the Higher Cryptogamia (see Bay Society’s 
Translation, p. 171, note), says :—“I wish to add a few words as to the meaning 
“of the expression ‘pro-embryo.’ By the word ‘embryo’ is meant the bud capable 
“of developing leaves and roots. Thus, we speak of the embryo of the onion, the 
“ potato, the hop. Now, when we find in the vegetable kingdom organs which dif- 
“ fcr from, and are of an essentially simpler structure than, the leafy stem-rudi- 
“ mcnts which afterwards spring from them, hut which must normally and 
“ necessarily in the course of their development produce embryos, I consider that I 
“ am justified in calling these organs ‘pro-embryos.’ Thus I designate as a pro- 
“ embryo the protonema of a moss, whether it owes its origin to the germination of 
“ a spore, or to the independent development of an individual cell of the leaf-bear- 
“ ing plant. I treat in the same manner the suspensor of Selaginella, of the 
“ Conifer®, and of the Phanerogamia. On the other hand, I do not designate as a 
“ pro-embryo the body which is produced directly from the germination of the 
“ spores of Ferns, Equisetace®, Bhizoearpe®, and Lycopodiace®, and which bears 
“ antheridia and archegonia.I call this organ a prothallium.” 
Mr. Berkeley, in his recently published Handbook of British Mosses, says :— 
“The threads arising from the spores (of Mosses) have received various names, as 
“ ‘ cotyledonoids,’ ‘ protonemata,’ ‘ proembryo,’ ‘ prothallus.’ The first of these is 
“ objectionable, because they have no analogy with true cotyledons, and the third 
“ because an intermediate stage must take place before the cell capable of impreg- 
“ nation is produced in the archegon, the result of which, after all, is a sporangium, 
“ and not an embryo. The production of the plant from the threads is rather gemmi- 
“ parous than embryonic, and I therefore strongly object to the term ‘ proembryo,’ 
“ which inevitably more or less directly leads to confusion. The second name at 
“ least is free from error; and if the moss plant may be called a ‘ thallus,’ the fourth 
“ name may be admitted. If new terms were not objectionable, I should prefer 
“ that of ‘ prophyton,’ which simply indicates that it is the forerunner of the true 
“plant.” 
