DEVELOPMENT OF BULBS AND TUBERS. 91 



XV. — Notes on the Development of Bulbs and Tubers. 



By Thilo Iraiisch. 



(Abridged from the German original.) 



[In the year 1850 an elaborate work on this subject appeared 

 in Berlin, from the pen of Mr. Thilo Irmisch, of Sondershausen, 

 under the title of "Zur Morphologie der monocotylischen Kuollen- 

 und Zwiebelgewachse." 'In two hundred and eighty-six 8vo pages 

 of letter-press and ten 4to plates crowded with figures, the author ex- 

 plained in great detail the manner in which about eighty European 

 plants form their bulbs, or tubers, giving a complete history of the 

 development of such parts. The manner in which the task was 

 executed was so complete, as to throw the clearest light upon the 

 history of such subterranean formations ; and thus demonstrated 

 to the intelligent reader the principles upon which tuberous and 

 bulbous plants should be cultivated and propagated. The great 

 length of the original renders it improbable that it will he com- 

 pletely translated, nor is it necessary, in a horticultural point of 

 view, that it should be, for many details required to illustrate 

 points of abstract science have little bearing upon horticulture, 

 or merely confirm the general conclusions at which Mr. Irmisch 

 has arrived. It would, however, be a real loss to English 

 Horticulturists if they were altogether deprived of the valuable 

 information contained in the author's pages, and it has appeared 

 desirable to introduce into the Society's Journal such an abridg- 

 ment of his observations as will enable the gardener to profit by 

 what among them is most essential to his art. The following 

 pages are therefore not to be regained as a translation of the 

 German original, but as a condensation of certain portions of it. 

 The woodcuts are copies of some of the engravings employed by 

 Mr. Irmisch to explain his descriptions.] 



I. LILIACEOUS PLANTS. 

 Allium ursinum, L. 



The slender bulb of this plant, when the fruit is ripe, presents 

 the following structure : — At its base is the axal portion of the 

 last year's plant, which is now very short, and which like the few 



