OF CILIATED INFUSORIA 237 



in these situations, away from atmospheric influence, Ciliate 

 matrices are formed only from amoeboid corpuscles. I had often 

 seen them swarming in such villi, and at other times had found 

 the villi containing an abundance of the ordinary discrete cor- 

 puscles that develop into Monads or Amoeba. 



I first obtained satisfactory evidence that some of the corpuscles 

 which appear in the villi are really embryo matrices of Kolpodae, 

 and then as to their rate of growth and development, during my 

 examinations of an infusion of Dutch Clover. On the nineteenth 

 day I found that the villi which had grown downwards from the 

 pellicle on this infusion contained a varying number of distinct 

 spherical amoeboid corpuscles. Three days later, some of the 

 corpuscles in other contiguous villi were found much larger, and 

 more like embryo matrices. Two days later still, other villi were 

 found containing a number of small but fully developed matrices, 

 in about one half of which the embryos were slowly revolving 

 within their cysts. 



Although different villi were examined on these separate occa- 

 sions, I have reason to beUeve, from examinations made as to 

 the state of many others of them, at the intervals above indicated, 

 that the rate of change observed, at three and two days 

 respectively, fairly accorded with the average rate of development 

 of these Ciliate matrices of amoeboid origin. 



The presence of these secondary matrices in the villi, often in 

 astounding numbers, was first discovered almost accidentally. 

 Only a very small portion of a pellicle remained on an old infusion, 

 prepared twenty-four days previously, which had been kept in a 

 dark cupboard the whole time, and had not been looked at for the 

 last eleven days. Before throwing it away, I cut off a small portion 

 of this pellicle, and, to my amazement, on examination found its 

 villi crowded throughout with new Ciliate matrices, such as may be 

 seen in the specimen shown in Fig. 51, A (x 15). The matrices 

 varied much in size, and in the thickness (and consequently in 

 depth of colour) of their brown cysts, as may be seen in B ( x 60). 

 Most of them contained embryos very slowly revolving ; none of 

 the cysts were empty, and no free Cihates of any kind could be 

 found in the infusion. The new brood had evidently not yet begun 

 to emerge. C ( x 60) shows how densely these cysts are massed 

 together in some of the villi. No stain has been used for either of 

 these specimens ; the natural brown colour of the cysts causing 

 them to appear as though they had been stained. 



