528 Angewandte Botanik. 



rence of scattered stereomatic Strands in the secondary leptome, 

 and finally the broad pith noticeable in the thin, lateral roots. 



The hypocotyl has a very small stele of onlj^ four collateral 

 mestome-strands with a little stereome on the leptome-side, and 

 interfascicular cambium is, also, developed, which gives rise to a 

 little secondary hadrome with a few vessels, but no libriform, and 

 no secondary leptome. A circular, and typical endodermis was 

 observed in the hypocotyl, and secretory cells occur in the primary 

 cortex. In the young, green shoots of the mature tree the structure 

 is the same in all respects, except that the pith is here divided 

 transversely by diaphragms of very thickwalled sclerotic cells, a 

 structure tha. seems common to the tribe LIagnolieae. In clder bran- 

 ches I detected sclerotic cells in the primary cortex, a character, 

 so far, known only from Magnolia according to Solereder, and 

 these sclerotic cells are especially frequent in the peduncle; in this 

 way the stem-structure of Liriodendron and Magnolia have this 

 peculjar feature in common. 



The leaf-blade has a bifacial structure with the stomata confined 

 to the lower face, and these have, sometimes, one pair of subsidiary 

 cells parallel with the Stoma; most frequently, however, there are 

 no subsidiär}^ cells differentiated. The palisade-tissue consists of 

 three distinct strata of a somewhat peculiar structure, since the 

 hypodermal layer is composed of very low, plump cells, while the 

 second represents high, and typical palisades, covering the third 

 Stratum, which resembles the hypodermal. The pneumatic tissue 

 consist of oblong cells, parallel with the surface. A very peculiar 

 structure is exhibited by the midrib, which contains a circular band 

 of about ten separate, collateral mestome-bundles, enclosing a cen- 

 tral pith, thus actually representing a stele; the leptome was in all 

 the Strands located in the periphery. Secretory cells were observed 

 in all parts of the chlorenchyma, beside in the water-storage-tissue 

 This is the structure of a leaf of a mature tree, and it differs in 

 several respects from that of the foliage of the seedling. The seed- 

 lings generali}^ grow in the shade of larger trees, thus the chloren- 

 chyma is somewhat modified, being composed merely of a homoge- 

 neous tissue like the pneumatic, described above. Moreover the 

 midrib contains here only one collateral mestome-bundle, vvhile 

 secretory cells abound, showing the same distribution as in the 

 other leaves. 



The characteristic point of the petiole has a distinct stele of 

 many separate mestome-strands as observed in the midrib. 



Theo Holm. 



Mohl, A., Chmelarstvi [Hopfenbau]. I. Teil. Geschichte 

 des Hopfenbaues. (Rakonitz, im Verlage der Ackerbau- und 

 Hopfenbauschule in Rakonitz in Böhmen, 1909. 4°. 222 pp. Preis 

 3,40 Kronen ö. W.) 



Schilderung der Entwickelung des Hopfenbaues seit den ältesten 

 Zeiten mit allen seinen Fortschritten in den letzten Jahrzehnten in 

 tschechischer Sprache. Die Technik wird in den anderen Teilen 

 behandelt werden. Matouschek (Wien). 



A-Tisgegeben : lö November 1909. 



Verlag von Gustav Fischer in Jena. 

 Buchdruckerei A. W. Sijthoff in Leiden. 



