and its Reproductive Cells, 33 



Contractility of the Diaphane. — On one occasion, while look- 

 ing at a large specimen of Amoeba princeps, I saw a rotatory 

 animalcule, something like Furcularia forcipata, Ehr., come up 

 to and bite it; and immediately after the bite had been given, 

 the surface of the Amoeba became puckered slowly towards the 

 point bitten. The Fwcularia then left i\ie Amoeba, but returned 

 again and inflicted the same kind of injury, when the same evi- 

 dence of contractility of the surface of the Amoeba took place ; 

 and this was repeated several times, at short intervals, until I 

 was fully convinced that the surface of the Amoeba manifested 

 the same appearance of irritability as muscular tissue under a 

 similar stimulus. I made at the time a sketch of the Amoeba, 

 which had a peculiar form of the villous tail ; and the whole is 

 introduced in PI. III. tig. 5, to make the facts connected with it 

 more intelligible and impressive. 



Sarcode or Endosarc. — This also, as in the other Amcebce, is 

 clouded, from several causes, but more especially from the pre- 

 sence of the moleculce or fine granules, with which it is so densely 

 charged that they seem to occupy half its bulk, and thus give it 

 an amount of opacity which contrasts forcibly with the trans- 

 parent diaphane. Moreovei', the sarcode suspends the granules, 

 digestive spaces and food, fat-globules, vesicula, and nucleus, all 

 of which rotate with it, and, in addition to the rotatory move- 

 ment especially, also contrast it strongly with the diaphane. 



Granules. — These, which far exceed the moleculse in size, 

 have such a rounded form and dark outline at the commence- 

 ment that they bear the appearance of organic bodies. But 

 from round they become elliptical, and lastly angular and crys- 

 talloid aggregates, based upon an octahedral form, which in 

 some instances is so perfect and so like that of oxalate of lime, 

 that, with their pinkish colour and dissolving without efferves- 

 cence under the influence of nitric acid, I am inclined to think 

 that they are crystals of this salt. (PI. III. fig. 1 c, &^, h, i.) 



They are present in the youngest as well as in the oldest forms, 

 and in number and size do not appear to bear any constant rela- 

 tion to the age and size of the individual ; for they are sometimes 

 more prominent even in young than in old specimens ; but, as a 

 general rule, perhaps they keep pace in number and size with the 

 age of the Amoeba : certainly, however, they do not pass into the 

 crystalloid angular form until the individual is pretty large and 

 well advanced in life. The largest I have met with did not exceed 

 the -Tj-oVoth part of an inch in length, and was composed of an. 

 irregular crystalline aggregate based apparently upon an octa- 

 hedral form. Their crystalloid form has been long since (1855) 

 figured and pointed out in Amoeba bilimbosa by Auerbach*. 

 * Loc. cit. tab. xx. figs. 12, 13, 



Ann, ^ Mag, N. Hist. Ser. 3. Vol. xii. 3 



