Vegetable Physiology for the Year 1836. 44-3 



quainted with no substance by which we can artificially {dis- 

 solve Amylum from without; and such a one must be pro- 

 duced in the cells of the potato in their growth. 



Hartig's views * that " in the evergreen fir trees the di- 

 gesting apparatus itself (the leaves are understood by this) 

 is carried from one year to the other, and on the contrary, in 

 the summer-green plants, the substance for the development," 

 have met with commendation from various quarters ; although 

 repeated observations show that the data on which that view 

 was founded are by no means correct. Wiegmann, sen.f se- 

 parated the Amylum from the wood of various trees ; to which 

 I will add the remark, that the occurrence of Amylum in 

 woods is rather an old observation. Wiegmann found, that 

 the powder in the end of the stem and in the root of Buxus 

 sempervirens was not coloured blue by iodine. Wiegmann 

 was not able to examine the fir trees, but is fully persuaded 

 that they would be quite destitute of starch; evidently, how- 

 ever, only because the hypothesis of Hartig is founded on 

 this. I find on the contrary in young fir trees, in Pinus as 

 well as in Abies and in Larix proportionally quite as much 

 Amylum as in many deciduous trees. 



Creuzburgj has published some microscopical experiments 

 on the globules of starch before and after vinous fermentation, 

 the results of which are represented in a plate drawn by 

 Corda. 



Various discoveries have been published during last year 

 on the occurrence of crystals in plants. Link very justly ob- 

 serves §, that crystals in plants might be compared with stones 

 and concretions in animals. They are so frequent that it 

 seems unimportant to mention all such cases. Link also con- 

 firms the observation that the spicular crystals seem to occur 

 more in the Monocotyledons, the conglomerate ones on the 

 contrary more in the Dicotyledons. Link however observes, 

 that these crystals occur not only in the cells, but also between 

 them ; an opinion to which I am able to oppose at present, 

 direct observations. In the tissue of Agaves and of Pontederia 

 cor data I thought that I had observed j| with certainty the 

 occurrence of some large crystals between the cells; but on 

 separating these crystals by macerating the tissue and by 

 using a higher magnifying power, I recently succeeded in ob- 



• Meyen's Year's Report for 1835, p. 37- 



t Flora 1836, p. 24, &c. 



% Additional Notices on the vinous Fermentation of amylaceous Sub- 

 stances. Erdmann and Schweigger-Seidel's Journ. f. Praht. Chan., ix. p. 

 299, &c. 



§ Element., p. 137. |] Meyen's Year's Report for 1835, p. 131. 



3 L2 



