243 
ness of the walls of the intestine of the lobster or, indeed, 
the existence of strings of vesicles bound together by a homo- 
geneous substance, like those which MacIntosh! found in 
Borlasia octoculata. In this way, also, is explained the fact 
that the cysts are often much smaller than the Gregarine to 
which they have to be referred. We know also through the 
researches of Stein,? of Bruch,? and, above all, of Lieber- 
kuhn,* what is the mode of formation of the psorosperms at 
the expense of the granular masses; but the question as to 
the manner in which the psorosperms are developed later into 
Gregarine, remained an enigma until the day when Lieber- 
kiihn® established in a decisive manner that a body exhi- 
biting amoeboid movements comes out of the psorosperms, 
and moves itself in the same way as the corpuscles which 
occur in suspension in the blood of the earth-worms, and 
which were observed and described for the first time by 
Morren.6 According to Lieberkthn the globules of the 
perivisceral liquid of the earth-worm are true Amebz, which 
must be connected with the development of the Gregarine. 
We find in this cavity structures which present characters 
intermediate between those of Ameebe and those of Grega- 
rine; and Lieberkiihn admits the direct transformation of ' 
the Amcebee into Gregarine. But it is very necessary to 
remark that the exactitude of the observation has been con- 
tested by Schmidt,’ and at the end of his work Lieberkiihn 
says himself: ‘‘ I am far from maintaining that all the Ameebze 
are born from psorosperms, or that all the Gregarine develop 
from Amcebe.’ ‘The observations which I have had the op- 
portunity of making on the successive phases of the develop- 
ment of the Gregarine of the lobster serve to fill up the gaps 
which the history of the development of these mono-cellular 
beings hitherto presented, and to elucidate some points which 
have remained obscure in this evolution. I have been able 
to follow step by step in the Gregarina gigantea all the suc- 
cessive transformations of the little protoplasmic mass which 
1 “Qn the Gregariniform Parasite of Borlasia,” ‘Quart. Journ. of Mic. 
Sci.,’ 1867. 
2 Stein, ‘ Miiller’s Archiv,’ 1848. 
3 Bruch, ‘ Zeitschr. fur Wiss. Zool.,’ Bd. ii, p. 110. 
4 Lieberkiihn, loc. cit. 
5 Ibid., p. 16, ‘Ueber die Psorospermien,” ‘ Miiller’s Archiv,’ 1854; 
“Notice sur les Psorospermies,” ‘Bull. de Acad. Roy. de Belg.,’ c.xxi, No. 7. 
7 eon. **De Structura Lumbrici terrestris,” ‘Acta Akad. Gandar,’ 1825, 
ae Schmidt, “Beitrige zur Kenntniss der Gregarinen,” ‘Abhandl. der 
Senkenberg Gesellschaft,’ 1854. 
8 Lieberkiihn, “ Evolution des Gregarines,”’ p. 27. 
