E. Ray LankesteiIj on the Gregarinida, 23 
4th. That fungi generally excite chemical decomposition 
in the soils on which they feed, and that it is the exclusive 
province of a certain class, when spread on the surface of an 
albuminoid, saccharine or alcoholic, or slightly acid liquid, to 
develope and grow, and during growth to give rise to either 
the alcoholic, acetic, or putrefactive fermentation. - 
Notes on the Gregarinida. 
By E. Eay Lankester. 
(With Plate V. 
(Eead Dec. 13th, 1865.) 
Though the minute organisms known as Gregarinida are 
remarkable for the great range of their distribution, appear- 
ing in various animals, both terrestrial and aquatic — from 
the Turbellarian worms up to the Brachyourous Crustacea 
and Mollusca, and even in Vertebrata — very little indeed 
has been added to our knowledge of their structure, de- 
velopment, or habitats, during the last few years. This is a 
matter not only for surprise, but also for regret, inasmuch as 
there are some important points in the history of these 
parasites still to be examined, and doubtless many new and 
interesting forms to be discovered. There is nothing to be 
recorded as having been ascertained with regard to Grega- 
rinida since the short article which I published nearly three 
years ago in the ^ Quart. Journ. Mic. Sci.* The researches 
of Lieberkiihn^ are generally accepted, and the great diffi- 
culty now is to discover the true sexual reproduction of these 
animals. 
Probable sexual reproduction.— The encystation of a single 
or of two Gregarinida, and their gradual resolution into a 
number of minute cells, at first circular, and afterwards, in the 
case of Monocystis Lumbrici, at least, assuming a navicula- 
like form, are well known. The pseudo-naviculse issue from 
the sac, and become free organisms. They have been formed 
by a process analogous to gemmation in the cyst ; and it is 
in their history, I believe, that the sexual reproduction of 
Gregarinida must be sought. It was formerly considered 
that the pseudo-naviculse individually developed into Grega- 
rinse by a single process of growth ; Lieberkiihnf showed that 
they undergo certain changes, their contents becoming con- 
* Since writing the above I have seen a short paper by Lieberkiihn, in 
* Muller's Archiv' for the last quarter of 1865. An abstract of it will be 
found in the " Chronicle." 
t ' Mem. de I'Acad. Roy. de Bruxelles,' 1854. 
