PHYTOGENESIS. 



In still smaller cytoblasts it appears only as a sharply i ir- 

 cuinscrihcd spot; this is most frequently the case, as in the 

 pollen of Richardia cethiopica, in the young embryo of lAnum 

 pallescens, and in almost all Orchidea (fig. 1G) ; or, lastly, 

 only a remarkable small dark point is observed. I have not, 

 as yet, succeeded in discovering it in the very smallest and 

 most transitory cytoblasts (in the leaves of Dicotyled ru for 

 instance). I have also found two in some very rare c but 



they occurred as exceptions to the general rule, and alu a\ - 

 where the majority exhibited the simple nucleus; for example, 

 in Chanuedorea schiedeana (figs. 6, 7), Seca/e cereale, Pimelea 

 drupacea (fig. 1-1) ; in the two latter I have sometimes found 

 even three (fig. 15). The observations I have made upon all 

 plants in which it was possible to trace the entire process of 

 formation completely, lead to the conclusion, that these small 

 bodies are formed earlier than the cytoblast (pi. I, figs. 1, 'J); 

 and I am almost inclined to conjecture that they are not alto- 

 gether unallied to the nuclei which Fritsche has shown to 

 exist in starch, and may probably indeed be identical with 

 them. 1 The size of this corpuscle also varies considerably, 

 from the extent of half the diameter of the cytoblast to the 

 most minute point, whose size could not be measured in con- 

 sequence of the thread in the diaphragm of the microscope 

 exceeding it so much in thickness. In the albumen of Ahics 

 excelsa I found it to average from 0-000015- 0-00009. ~> Paris 

 inch; in Pimelea drupacea, from 0-00029-0-0003. Sometimes 

 it appears darker, at others brighter, than the remaining mass 

 of the cytoblasts. In general it has more consistency than 

 the rest of the cytoblast, and continues sharply defined alt or 

 that has been changed by pressure into an amorphous mass, as 

 in Pimelea drupacea for example. 



There is a second point, on which I must say a few words, 

 in order to be enabled to express myself more briefly hereafter 

 without being unintelligible, which relates to the different 

 inorganic substances that occur during the vital process oi 

 plants, and pertain to the scries of starch and woody tibi I 



make no pretensions whatever to a complete enumeration of all 



1 More accurate investigation of the structure <>f the starch granule* ha- ihown 

 this supposition to he quite untenable. 



