38 POPULAR ILLUSTRATIONS OF 



of Claparede's figure of this creature at Fig. 39. It will be noticed 

 that a large branch of sarcode appears to grow out of the body of 

 the animalcule, and divide and subdivide until it attains the length 

 in some instances of ten or twelve times that of the body. When- 

 ever these rootlike processes or pseudopodia meet, they unite 

 together, and then a net is formed of considerable size. When the 

 prey of the animalcule, which may be a near relation or one of the 

 Algae, comes into contact with the net, it sticks there ; how it sticks, 

 or why, I do not pretend to say, but that it does so is quite certain, 

 and, whatever it may be, its race is run, for the sarcode net imme- 

 diately takes it in not to show it hospitality, neither to draw it 

 down to its respected parent who formed it into a net, but actually 

 in the most selfish manner possible to digest it itself. And now we 

 find out in earnest that Mr. L. Wageneri is an arrant impostor, for 

 he has actually converted a part of himself into a net, which seizes, 

 devours, and digests its prey in that form, while he remains quite 

 still at the bottom of the drop of water. The digested food then 

 becomes common property, and feeds the general corpus of Mr. 

 L. Wageneri. This animalcule is 1 -400th of an inch in size ; with 

 its net, l-100thto l-40th of an inch. Now it will be found that the 

 outside skin or ectosarc of these Beticularia is harder than that of 

 the naked Amoeba. It is not at present, however, in any degree 

 like a shell covering. 



But following out the gradual development of shell in these 

 creatures, without for the moment attending strictly to classification, 

 or stopping to discuss the question whether an Amoeba with long 

 processes is higher in the scale than those with short ones, let us 

 look at the next group which this mode of investigation will bring 

 before us. The curious-looking thing shown in Fig. 40 belongs to 

 the genus Difllugia, and here the body is covered with what is called 

 a " test " the word " shell " being reserved for those made of cal- 

 careous matter. This "test" is thought to resemble the chitine 

 which forms the external skeleton, such as the elytra, of beetles. I 

 am, however, strongly inclined to the opinion that this is only 

 a guess, as we have no evidence that the " protoplasm " has 

 yet been differentiated into chitine. The pseudopodia, short and 

 stumpy, are seen in these species protruding in a supper-seeking 

 attitude from the mouth of the test. Fig. 41 shows an example of 

 another genus, Arcella, which carries its test upon its back. Note 

 here also the short stumpy pseudopodia possessed by this creature, 

 you cut off a small piece of the end from one of these organs, it 

 will become developed forthwith into a test-carrying Ehizopod, like 

 its respected parent ; and the same with Difflugia. And mark, they 

 never make a mistake that is to say, the bit of Arcella never is 



