THE CELL DOCTRINE. 75 



Sea, of a non-nucleated amoeba, by Heeckel* in the 

 Mediterranean, of a non-nucleated protozoon (Pro- 

 togenes primordialis), and* by Cienkowskyf of two 

 non-nucleated monads, namely, Monas amyli and 

 Protomonas amyli. Hseckel says of his Protogenes 

 primordialis that it multiplies by division. Strieker's J 

 own observations on the fecundated egg of the frog, 

 incline him to adopt the view of Briicke, and to omit 

 the nucleus in a theory of elementary organization. 

 With these general considerations in the history 

 of " protoplasm," we are the better prepared to take 

 up the theory of 



DR. BEALE, 1861. 



In April and May, 1861, Prof. Lionel S. Beale 

 delivered the lectures before the Royal College of 

 Physicians, of London, in which he promulgated 



* Hseckel, Zeitschr. f. w. Zoolog., 1865, Bd. xv. 



f Cienkowsky, Max Schultze's Archiv, 1865. 



J Strieker, op. citat. 



$ In a recent paper by Prof. Hseckel, 1 he states that the "pro- 

 toplasm theory" was brought forward in its elementary form by 

 Cohn, 2 in 1850, and by linger, in 1853. It was further developed 

 in 1858, and finally completely established in 1860, by Max Schultze. 

 Hseckel also considers that by no phenomena is the correctness of 

 this theory so thoroughly proved, and at the same time in so sim- 

 ple and unassailable a manner, as by the vital phenomena of the 

 Monera, by the processes of their nourishment and reproduction, 

 sensitiveness and motion, which entirely proceed from one and the 

 same very simple substance, a true "primitive slime." 



1 Ilaeckel, Ernst, Monograph on the Monera, and Remarks on the Pro- 

 toplasm Theory. Q. Jour. Mic. Sci., Apr., July, and Oct., 1869. 



2 Cohn, F., Nachtrage zur Naturgeschichte des Protococcus pluvialis ; 

 Nova Acta Ac. Leop. Carol., vol. xxii, pars ii, p. 605. 1850. 



