ZYGORPOB 1 . IT 



activity . A similar behavior of the granule* in the bodies of smaller 

 I smids, and in the cells of filamentous .1///", i- < 1 1 1 1 1 observable, 

 particularly in unhealthy plants. So satisfactory explanation of 

 these movements has yet been given. I" ~ 1 1 1 - they appear a 

 mystery, but, are they more mysterious than the circulation of 



l>l I in our arteries and veins, or than thai of the so-called cydoria 



in the higher plants? Nearly, it' nol quite all vegetable germinal 

 matter, displays some spontaneous activity, and it is inure than 

 probable that the like characteristic seen in the Desmids, must l><- 

 :i-<ril).-.| to the same causes whatever th<\ ni:i\ be. 



mi i Tin k \ ri< >\ 



Multiplication among the Desmids takes place l\ two pro 

 IIh one is simply a division and growth, tin- other is through 

 what in;i\ be termed sexual intervention. 



I he firs! process i- mereh :i modification ><\ ordinary vegetative 

 growth, thai is to say, a |ieculiar cell multiplication by division. 

 Plan XII, fin 6, are two semi-cells of a Docidium, which have 



se|>a rated by the development ><\ shorl pi*ocesse> lig. 7 ; tl 

 primarily ven small, commence their L r i"\\th from "in of the 

 centre ol the base of each semi-cell. The figure represents them 

 somewhat advanced ; they develop rapidly, and -<>n become exacl 

 counterparts of the original mother-cells, then ili\ seiiarate. Tim- 

 two cells are develo|>ed from one; the same process i- repeated, 

 the tw<> produce four, the four < i l^I 1 1 . and so on. 



Plate XI \ ,figs. 12, 13, represent a Oosmarium f the one the perfect 

 plant, tin' other in process of division ; the endsSire the halves of 

 the mother-cell ; the parts between, the partially developed forma of 

 the new semi-cells. Plate XVI, fig. 27, represents a similar 

 growth of :i denticulate form ; the teeth are nol apparenl until the 

 young part- have attained nearly their full suse. 



Plate XXXVIII, fig. 8, i- a series of four kRcraM* Has tnmoata, 

 which represent the stages of growth by division ; a II producing 

 two, and the two, four, under the ratlin- unusual circumstance of 

 adherence alter division ; onlya fragment of the series is shown in 

 the figure. Fig. 11 is a similar fragmentary series of adhering cells 

 which must originally have numbered no less than Bixty-four. I 



counted thirty-eight whicl ul<l not have occurred in a regular 



process of division. 



