THE LOWEST FORMS OF LIFE. 
153 
perfect organ ; so much so, that the contractions and dilata- 
tions in both cases are known to physiologists by the same 
scientific designations, the ‘ systole 5 and the f diastole. 5 In 
another of the Infusoria I have seen this action very perfectly 
displayed. The animalcule is called Glaucoma scintillans 
(the f scintillating or sparkling Glaucoma 5 ) ; and here, when the 
vesicle contracts, five secondary ones make their appearance 
around it, and into these spaces the fluid penetrates. As the 
central vesicle dilates again, its satellites contract and disappear. 55 
(PI. viii., fig. e.) 
“ And are there any veins or arteries in the Infusoria ? 55 
“ I have not observed anything analogous to these vessels 
in the animalcule just named ; but in another ( Paramecium 
caudatum, pi. viii., fig. 5), I have noticed a number of little 
channels radiating from the contractile space.* These seem to 
represent the arteries; and when the vesicle contracts, they 
expand and become visible. Near the vesicle they are bulb- 
shaped, and they become smaller as they recede from the 
f heart. 5 Just as in the case of the smaller vesicles that sur- 
round the central one in Glaucoma, these arterial vessels 
disappear as the contractile vesicle expands and receives back 
its contents. Is it not wonderful how the designs and opera- 
tions of the Infinitely Great may be traced even in His 
infinitely small creations ! 
“ And now, having explained to you the digestive and circu- 
lating process in Yorticella, and some of the other infusorial 
animalcuke, I must conclude its history by describing its mode, 
or rather, I should say, its modes, of reproduction. It is repro- 
duced by at least three, and, according to some physiologists, 
by four, different methods. The first is by subdivision : that 
is the most simple and the most easily watched ; indeed 
here is one undergoing subdivision : you had better all inspect 
it before I explain the process (pi. vii.). You will notice that 
there are two calyxes or cups upon one stalk. 55 
“ Yes; and one of the cups has a double circlet of cilia, one 
at the rim and another close to the stalk. What is the use of 
the second circlet ? 55 
“ I will tell you presently. 
“ When a Yorticella is about to subdivide, it becomes in- 
dented longitudinally ; that is, from the stalk to the rim. This 
indentation becomes deeper and deeper until the calyx is 
separated into two parts, as you see, both remaining on the 
same stalk (pi. vii.). Presently the second circlet of cilia 
is formed on one of the cups (I say presently, for the whole 
process of subdivision rarely occupies above an hour) , and these 
new ciha, by their rapid vibrations, twist the cup off the stalk. 
* P. caudatum has two such spaces. 
M 2 
