238 F. 0. BOWER. 



name of '' starch-forming corpuscles " (Starkebildner) . It is 

 true that these bodies had ah-eady been recognised by other 

 writers/ and even clearly represented in drawings; further, that 

 Criiger had specially pointed out his " Uebergangsubstanz " as 

 the substance which is in the very process of being converted 

 into starch, and discussed the question of its containing 

 nitrogen ; Naegeli ^ and Trecul, on the other hand, scouted this 

 idea. In their hands the structural question, whether a 

 specialised mass of protoplasm is or is not present in connec- 

 tion with growing starch-grains, became so involved with, and 

 absorbed in what was to them the larger question, viz. whether 

 the starch-grains grow by apposition or by intussusception, 

 that they failed to apprehend that fundamental structural 

 point recently brought out by Schimper, which will now be 

 looked upon as the key to their larger question. No doubt 

 the imperfection of microscopical methods had much to do 

 with the long dormancy of this important subject, and it may 

 be safely concluded that improvements in methods have given 

 the impulse to those recent researches, which it will be the 

 object of this essay to discuss. 



Pirst among the writers of this period of revival comes 

 Schimper, and no doubt to him belongs the merit of again 

 breaking up the old ground.^ In the same year as his first 

 paper was published, the Inaugural Dissertation of Dehnecke 

 appeared, dealing with the subject of " non-assimilating 

 chlorophyll bodies." His results harmonise on the whole with 

 those of Schimper, and consequently do not agree with the 

 description given by Molisch and Haberlandt (•' Bot. Zeit.,' 

 1877, No. 23). According to these authors the assimilating 

 chlorophyll bodies arise, in starchy cotyledons, by the sur- 

 rounding of starch - grains by chlorophyll substance ; this 



' Naegeli, ' Zeitsch. f. wiss. Bot.,' 1845, Heft i, p. Ii9 ; iii, p. 109. 

 Criiger, 'Bot. Zeit.,' 1854, p. 41, comp. figs. 12, 13, 14. Trecul, "Des 

 formations vesciculaires (1858)," 'Ann. Sci. Nat.,' 4""^ serie, tome x, p. 234. 



" Naegeli, ' Stiirkekornei',' p. 220. 



* N.B. — His paper above-mentioned was forwarded from America, and was 

 received by the editors of the 'Bot. Zeit.,' July 27, 1880. 



