86 THE HISTORY OF CREATION, 
and which possessed the form of a single plastid. At 
first the entire body of one of these small primary plants 
consisted only of a most simple cytod (a plastid without 
kernel), and afterwards attained the higher form of a 
simple cell, by the separation of a kernel in the plasma. 
(Compare above, vol. 1. p. 345.) Even at the present day there 
exist various most simple forms of Aleze which have devi- 
ated but little from the original primary plants. Among 
them are the Algz of the families Codiolacese, Protococ- 
caceze, Desmidiacez, Palmellaceze, Hydrodictyez, and 
several others. The remarkable group of Phycochromaceze 
(Chroocoecaceze and Oscillarineze) might also be comprised 
among them, unless we prefer to consider them as an in- 
dependent tribe of the kingdom Protista. 
The monoplastic Protophyta—that is, those primary Aleve 
formed by a single plastid—are of the greatest interest, 
because the vegetable organism in this case completes its 
whole course of life as a perfectly simple “ individual of the 
first order,” either as a cytod without kernel, or as a cell 
containing a kernel. 
Among the primary plants consisting of a single cytod are 
the exceedingly remarkable Siphonez, which are of con- 
siderable size, and strangely “mimic” the forms of higher 
plants. Many of the Siphoneze attain a size of several 
feet, and resemble an elegant moss (Bryopsis), or in 
some eases a perfect flowering plant with stalks, roots, 
and leaves (Caulerpa) (Fig. 17). Yet the whole of this 
large body, externally so variously differentiated, consists 
internally of an entirely simple sack, possessing the negative 
characters of a simple cytod. 
These curious Siphonez, Vaucherize, and Caulerpze show 
