2 Anatomie. — Biologie. 



Untersucht wurden ausgewachsene Theile von : Carduus crispns L. 

 V. denudatus (Tausch.), Aster chinensis L., Silene dichotoma Ehrh., 

 Cerastium vulgare Hn., C. arvense L., Stellaria graminea L., Epilobiam 

 collinum Gmel., Oxalis acetosella L. 



3. Arten mit hauptsächlich dünnwandigen, wasser- 

 geiüllten Trichomen. Diese Trichome dürften nach Verf. zarte 

 Pflanzentheile gegen Transpirationsverlust schützen. 



Untersucht: Scorzonera hispanica L., Veratrum album L. ß. Lobe- 

 liannm (Bernh.), Solanum tuberosum L., Narthecium ossifragum (L.), 

 Epipactis Helleborine Gr., E. palustris (L.), Goodyera repens (L.). 



4. Arten mit überwiegenden Drüsenhaaren. 



Crepis paludosa (L.), Rubus odoratus L., Antirrhinum majus L., 

 Adonis aiitumnalls L., Viola canina L. 



5. ArteU;, welche hauptsächlich Rauheit bewirkende 

 Haare besitzen. Diese sind gewöhnlich kurz, spitz, dickwandig, iuft- 

 führend,, im oberen Theil ohne Lumen. 



Untersucht wurden: Brachypodium pinnatum (L.), Lolium tcmu- 

 lentum L., Poa trivialis L., Agrostis canina L., A. vulgaris With., Apera 

 spica venti (L.), Baldingera arundinacea (L.), Anthoxanihum odoratum 

 h., Hierochloa odorata (L.) f. firma Nyl., Carcx Oederi (Ehrh.), C. panicea 

 L., C. pilulifera L., Anchusa arvensis L., Alyosotis palustris L., Nemo- 

 phila insignis Benth., Omphalodes linifolia (L.), Gentiana campestris L., 

 Rhinanthus major Ehrh., Phaseolus multiflorns Willd. 



Die „Veränderlichkeit" der Trichome betrachtet Verf. von denselben 

 Gesichtspunkten wie in seiner im Bot. Centralbl. 1903. 2. p. 580 referierten 

 Arbeit. Grevillius (Kempen a. Rh.). 



Mac Dougal, D. T., Delta and Desert Vegetation. (Bot. 

 Gaz. Vo!. XXXVIII. p. 44—63. 7 fig. in text. july 1904.) 



A description of the sub-tropica! delta oi the Colorado 

 river and of the he gravel and sand desert mesas oi Sonora 

 and Baja California with w^hich it is in direct contact. The 

 important plant iorms are enumerated. Much of the delta 

 region is subject to floods or tidal influences and Supports a 

 growth of considerable luxuriance in which the elements are 

 present in pure formations. The larger v^oody plants frequently 

 show a xerophilous foliage owing to the higher temperature of 

 their sub-aerial portions in the dry air, in comparison to the 

 low temperature of their subterranean organs surrounded by a 

 varyingly saline soil water. The mesas near the northern part 

 oi the Gulf of California appear to present the most ex- 

 treme desert conditions found in North America. In his 

 meteorological observations the author notes the interesting fact, 

 that the humidity of the air decreases with great rapidity away 

 from the river itself. H. M. Richards (New York). ' 



Spaulding, V. M., Biologie al Relations of certain De- 

 sert Shrubs. 1. The Creosote Bush (Covillea trl- 

 dentata) in its Relation to Water Supply. (Bot. Gaz. 

 Vol. XXXVIII. p. 122—138. 7 fig. in text. Aug. 1904.) 



Covillea tridentata is one oi the most characteristic species 

 of the lower Sonoran zone and is found on a great variety of 

 soils with different exposures, in Company with species that are 

 less adaptable to their surroundings. In the matter of water 



