122 ^^l•. II. J. Carter on the Organization of Infusoria. 



hope to give uilotaik'il account hereafter), these granules, during 

 the formation of the globular cell within the body, which 

 enclosed the materials from which the Plasconia was ultimately 

 developed, became congregated together at the posterior ex- 

 tremity of the Oxytricha, and remained there in a roundish mass, 

 shut out from the cell, until the latter burst for the liberation 

 of the Plcesconia, when, with the deciduous coverings, they 

 passed into dissolution. Of the nature of their office I am 

 ignorant, but they are sufficiently remarkable and constant to 

 demand particular notice. 



In the development of the sponge-cell, a similar set of large 

 granules makes its appearance at a very early period, and 

 increase in number and size until they form as remarkable a 

 feature as those above noticed. At this time they are about 

 T(jUoo °^ ^^ ^"^^ ^'^ diameter, of an elliptical shape, and of a 

 light amber colour by transmitted light ; they arc the colour- 

 bearing granules or cells of Spongilla, and give the colour of 

 chlorophyll to this organism when it becomes green. 



Such granules would appear to be present also in the earliest 

 forms of Amaba, since they may be seen in mono- and cUjilo- 

 ciliatcd monads, which, on losing these appendages, become 

 j)()lymorphic, and assume all the characters of Amwba. Here 

 they not only resemble the granules of the sponge-cell, but at 

 the same time aj)pear to be of the same kind as those above 

 described. Neither is it uncommon to see polymorphic cells, 

 precisely like Amceba, bearing granules coloured like those of 

 the sponge-cell ; but the resemblance between the two organisms 

 is so great, when the latter is free, that it is impossible to say 

 which is which : however, they are greenish-yellow and ellij)tical- 

 elongate in the foot of Dijfflugia proteifonnis, Ehr., which cannot 

 be confounded with the cell of Spunyilla. That these granules 

 are not ovules in the sponge-cell, any more than in the Infusoria, 

 their colour alone is sufficient to determine. 



Digestive Globules. — We shall use this term for spherical 

 spaces of the sarcode, which are filled with water, and generally 

 contain more or less food (Hgs. 3 e, G5 b, 74 d). They are 

 formed in Vorticella and Paramecium in the following way, viz. 

 as the particles of nutritive matter are drawn into the vortex of 

 the buccal cavity, by the cilia which are disposed around its orifice 

 for this jjurpose, they are forced down, with a certain amount 

 of water, into the sarcode at the end of it, where they at first 

 f<jrm a j)ouch-likc dilatation, which sooner or later becomes 

 constricted close to the buccal cavity, and, having been thus 

 8Cj)arated from it, pa.s.scs off in a spherical form into the midst 

 of the sarcode (figs. 05 c, 74 cc). The formation of one globide 

 IS soon followed by that of another; and so on successively the 



