H. BOTANY AND HORTICULTURE. 373 



the strips of tin, and their other ends stuck through the felt. 

 The electric current is immediately established, one half of 

 the felt having positive, the other negative electricity. On 

 another piece of moist felting, entirely disconnected from the 

 battery, is placed also some cress seed, in order to observe the 

 difference in the growth of the two portions of seed. After 

 the lapse of four days, the seed on the positive side of the first 

 piece of felting gave signs of germination, while their hulls 

 were shriveling up, and had become black. On the negative 

 side of the felting the seeds were at the same time swollen, 

 and their hulls, which retained their natural color, Avere be- 

 ginning to burst. In six days' time the first shoots broke 

 forth. The seeds on the second plate of felt, which were not 

 under the influence of electricity, first sprouted many days 

 later. The most peculiar result of this trial was, however, 

 that while on the negative pole, where there was every sign 

 of stronger development, the root sprout sank downward into 

 the moist felting; on the other hand, on the positive felt the 

 root sprouts rose upward from the blackened and dried iip 

 seeds. The upward movement of the root sprouts has al- 

 ready, in 1867, been observed by Blondcau ; but he ascribes 

 it to the influence of electricity in general, and not especially 

 to the positive electricity. 7 6", 1873, 411. 



NEW TEXT-BOOK OX BOTANY. 



A translation is being prepared in England of the niost 

 thorough text-book of botany in existence. Dr. Julius Sachs' 

 Lehrhuch der Botanik. The Board of Studies of the Natural 

 Science School at the University of Oxford, in their recent 

 programme, recommended the book to candidates for de- 

 irrees; and the delesiates of the Clarendon Press of that uni- 

 versity have acquired from Dr. Sachs the right of translation 

 and the use of the numerous and excellent wood blocks. Mr. 

 A. W. Bennett has undertaken for the university the trans- 

 lating and editing of the English work, which will probably 

 become the standard publication on the subject. 



COHX ox BACTERIA. 



Dr. Cohn, who has written a great deal upon bacteria, de- 

 ques them as " chlorophyl free cells of spherical, oblong, or 

 cylindrical form, sometimes twisted or bent, which multiply 



