10 Mr. H.J. Carter on the Development of Gonidia 



cells there ap])ears to be no brown matter, but from the red gra- 

 nules, which are the equivalents of the green disks in the fan- 

 shaped group of cells forming part of the capsule of the globule, 

 being attached singly or in groups to their periphery, it may 

 reasonably be inferred that this is the position of the so-called 

 brown matter in them. 



After a certain time, the gonidial substance with its bright 

 refractive granules makes its appearance in different parts of the 

 brown matter, as if it were rising out of it, and then to one side 

 in a distinct mass which acquires a mulberry-form and separates 

 into gonidia ; or the gonidia may be fully developed inside or in 

 the midst of the brown matter before they make their appear- 

 ance. The gonidial substance has already been described^ as 

 well as the bright refractive globules, which do not alter in 

 colour by contact with iodine. Making its appearance then in 

 this way, it is not extraordinary that the gonidia, in addition to 

 their own peculiar blue-coloured mucus, which colour, as before 

 stated, appears to depend on its granular contents, should, for 

 the most part, also contain more or less of the refractive globules, 

 and occasionally a fragment of the brown matter, which is the 

 case. 



I have already described the commonest form of gonidium, 

 but there is still another about twice the size, viz. 2150th of an 

 inch in diameter, which although not so frequent, is nevertheless 

 sufficiently so to show, that there are two sizes more common 

 than the rest ; for we shall presently see, that the gonidial sub- 

 stance may occasionally come out as a w^hole, or in gonidia of 

 all sizes below its original bulk. This large gonidium generally 

 presents itself under a circular or globular form, with a single 

 cilium, but it is sometimes seen ovate or spindle-shaped like the 

 smaller one. It must be obvious to all, that a polymorphic cell, 

 such as the gonidium is, can have no constant figure while in a 

 state of activity ; hence at one time it may be of one shape, and 

 at another of another ; but when under polymorphism and the 

 cilium has disappeared, a group of gonidia will evince a strong 

 tendency to assume the same kind of figure generally, whatever 

 that may be. Thus, just after they become stationary, the form 

 of Actinophrys Sol seems to prevail ; then the digitated form for 

 progression ; then the diffluent form, which appears to be pro- 

 duced by the more internal protoplasm bursting through that 

 which is becoming hardened on the surface ; and lastly, the 

 tardy, rhizopodous form which I have mentioned; but I will 

 not vouch for this sequence, and only instance it for example. 



I have already alluded to the variety in size of the gonidia, 

 but this is an exception to the general rule, for the smallest 

 gonidial cell, in which only one gonidium is developed, yields a 



