224 Transmutation of Form in certain Protozoa. 



and thence passes to Callidina elegans, thus tracing one of the 

 phases of growth by development from the simple form oiMonas to 

 some of the more complicated animalcules or Entomostraca. I shall 

 hope in a future communication not only to trace the Faramoecium 

 from the monad, but also to show that the " choses exterieures " 

 being altered the monad may become a Chlorocoecus, an Oscillatoria, 

 a Lynghya, a moss, a lichen, an Amoeba, or a Mueedo. 



There may be many other forms which it may be developed to, 

 but for the present I must content myself with the changes in 

 Faramoecium to introduce this vast subject fraught with so much 

 importance to our knowledge of the Darwinian hypothesis, the 

 question of epidemic disease, and the formation of the green sub- 

 stratum of Protophyta. 



May 20<A, 1868, in a liquid containing Oscillatoria and Lynghya 

 (May llth) I observed a Faramoecium first divide itself into two 

 portions, one globular and the other elongated. They then became 

 attached, and finally the globular was absorbed by the elongated 

 portion. The operation was completed in about three or four minutes 

 (see Figs. 1, 2, 3, 4, 5 and 6). 



On May 9th, 1869, I watched a Faramoecium divide, as in Figs. 7 

 and 8, and then swim away, one globular, the other oval (see 

 Fig. 9). 



On the same day I watched two Faramoecia, a globular and elon- 

 gated, become one pyriform body. 



Sept. 17th, 1869, I saw the Fig. 10 separate into Fig. 11. 



May 9th, 1869, I watched the spot on Fig. 12 slowly disappear, 

 and the Faramoecium become Fig. 13. In further proof that this spot 

 is caused by contraction of the cell wall, I saw on July 25th, 1869, 

 the Fig. 14, in which the contraction at the bottom shows the 

 situation of this spot ; but as conclusive evidence I saw the Fig. 15 

 change its situation, and the contracted spot became visible at a side 

 aspect, as seen in Fig. 16 ; and on 9th May I saw several green cells 

 protrude amoeboid pouches or globules of sarcode from the side, but 

 more especially the Faramoecium represented in Fig. 17.* But now 

 to come to the proof of what I desire to show in this paper, namely, 

 that Vorticclla is only a stage of Faramoecium, and that Callidina 

 elegans is a developed form of Vorticclla, I must refer to Figs. 18 

 to 21. 



Sept. 18th, 1869, I watched Fig. 18 change into Fig. 19, then 

 throw out cilia at one end, as in Fig. 20, and finally swim away as a 

 perfect Vorticclla, as Fig. 21, with a telescopic stem.f On the same 

 day I again watched the fissation of a single Faramoecium, with two 

 germinal spots, slowly into two perfect globular bodies, neither of 

 them having any spot. At the same time, under the influence of 

 opium. Fig. 22 changed its spot from its position there represented 



* See pi. XXV. (fig. 2a), ' Micrographic Dictionary,' by GriflBth and Henfrey. 

 t I have often in previous observations seen the telescopic tail protruded by 

 objects having all the appearance of a detaclicd Vorticclla nehulifera. 



