231 j\Ir. II. J. Carter un the Organization of Infusoria. 



complication, arc observations merely put forth for what they 

 may ])rove worth. At the same tinie, it apj)ears evident that 

 each orgTin must have its j)ro]K'r cell, and this cell its proper 

 mode of iin))rtirnative reproduction, just as much as tlu; most 

 complicatrd beings of wiiich it forms a jiart ; while -the granu- 

 lating of the nucleus of a cell to furnish fertilizing germs for the' 

 process of generation, when a simple division of it only is re- 

 quired for common reproduction, is perhaps not the least un- 

 tenable view that may be held on the subject. 



In Phyaactis saccafa, Kg., the s})herical, terminal cell of the 

 snake-like iilaments is tilled or lined with a homogeneous, trans- 

 lucent substance, in one part of the circumference of which is a 

 nucleus, and this part is invariably next the last granuliferous 

 cell of the filament (fig. 70 Z/), which with the four or five fol- 

 lowing ones unite together to form the elongated club-shaped 

 sj)orangium (fig. 71). When the sporangium is completed, the 

 spherical cell is seen to be united to it by a kind of neck, but 

 the nucleus and its homogeneous contents have disappeared, 

 that is, have passed into the sporangium (fig. 71 a). While 

 here and there may be seen spherical cells unattached to (pro- 

 bably separated from) their filaments, some of which have a gra- 

 )iular substance growing out in a linear form from the nucleus 

 (figs. 72, 73). Hence then, as we have the nucleus of the sphe- 

 rical cell applied to the terminal cell of the granuliferous chain, 

 a tubular prolongation connecting it with the sporangium, the 

 disappearance of the nucleus and other contents of the spherical 

 cell after the formation of the sporangium, together with a gra- 

 nular growth from the nucleus of this cell when the sporangiimi 

 is in i)rocess of formation, I think it may fairly be inferred, that 

 the chief part which the s])herical cell adds to the sporangium is 

 this granular growth from its nucleus. 



Development of the Ovule. — In SpongiUa and Euglyphn, this 

 appears to take place by the passing of the transparent, faint- 

 yellow film, which lines the interior of the capsule, into an opake, 

 yellowish, granuliferous membrane ; synchronously with which 

 it becomes more marginated towards the capsule, and presents, 

 in the centre, a jiellucid area, in the middle of which, again, is 

 a minute granule or body, which appears to be the rudiment of 

 the nucleus (fig. 59). Frequently, also, another layer, as before 

 stated, is seen in the ovules of SpongiUa external to the capsular 

 one, and this appears to be endowed with locomotive power, as 

 it generally presents a parabolical shape, extended out from one 

 side of the ovule (fig. 40 a) ; after which the ovule in each be- 

 comes transformed, ap])arently wholly, into a polymorphic, rep- 

 tant Ilhizopod (fig. 30 i, k). The same process, modified, aj)pears 

 to take place in the ovules of Euglena. Thus in E. viridis, where 



