234 PHYSIOLOGICAL BOTANY. 



In an appendix upon the laticiferous vessels, he advises us 

 not to read upon the subject at all, because most of what 

 is stated upon it involves much contradiction ; he quotes 

 Bischoff and Schleiden. He has not mentioned my re- 

 searches. In the first part of my Lectures on Botany, he 

 would have found much upon this subject ; and also many 

 figures in the Plates to the first part of my Anatomy of 

 Plants. 



Researches on the earliest Modifications of Organic 

 Matter and the Formation of Cells. By M. Coste. 

 Comptes rendus, 1845, 2, 911, 1396. This memoir 

 principally treats of the animal cell, and tends more by 

 reasoning than experiments to show that the theory of 

 the production of cells by the nucleus is not based upon 

 satisfactory investigations. 



The preceding experiments upon the manner in which 

 new cells are formed, induced me to make some extended 

 observations myself. Thus, when our object is to become 

 acquainted with the manner in which cells are reproduced 

 in the Phanerogamia, without confusing the phenomenon 

 with others not appertaining to it, the method of proceed- 

 ing used by linger is the best. With this view I caused 

 some bulbs of Allium cepa to grow in a hyacinth glass 

 filled with water, and made marks upon the roots which 

 had grown out, with Indian ink, one close to the bulb, 

 another close to the conical apex, and a third midway 

 between the two former. In a few days the roots had 

 grown very considerably, the conical apex not so, as far 

 as was distinguishable, the base had grown but little ; 

 the portion between the apex and the middle had grown 

 most. The latter portion was again divided in the middle, 

 and it was found that the part nearest to the apex had 

 again grown very considerably, whilst that next the middle 

 had grown but little. On making a longitudinal section 

 from the mark at the apex to near the upper mark, treat- 

 ing it with nitric acid, and then iodine, a great many short 

 cells were seen near the apex, these were found gradually to 



