BOTANY. ,^05 



removal of both bark and wood in the case of those trees which i)(>s- 

 sessed no trne lieart wood, namely, the ma])Ie, beech, and horsccliestnnt. 

 The oak and laburmun, from which both bark and wood were rcnioved 

 fared quite diflereiitly. The oak was killed above the point where the 

 tree was rinj2:ed, but continued to live below it. The laburnum was 

 killed outrij^ht. 



Tlfc experiments show that in those species of trees which form no 

 true heartwood the water ascends freely through the central ])ortion 

 of the stem as well as through the outer portion; Avhile with those 

 species which i^ossess a duramen the ascent of the water is conlined 

 to the region of the sapwood. A description of the appearance of the 

 stems the following season is given. It is stated that in the case of 

 the horse-cliestnuts, where the bark only had been removed, a callus 

 was formed on the cut edge of the cambium, both above and below. 

 Where both bark and wood were removed, a callus was formed above 

 and below, and a few shoots appeared from the lower callus. \n the 

 case of the maples, where the bark only had been removed, a 

 callus was formed above but none below; ami where both bark and 

 wood were removed, a callus was forjued over each of the cut 

 surfaces. With the beeches from which only the bark w as removed, 

 a callus was formed on both surfaces, but principally above. Where 

 both bark and wood were removed, a slight callus was formed below 

 but none above. In the case of the oaks, of which two different species 

 were used, in the one from which the bark only had been removed a cal- 

 lus was formed above and below. In the other, from which both bark 

 and underlying sapwood were removed, no callus Avas formed, although 

 the stem continued to live and send out shoots from its sides. The 

 laburnum from which the bark was removed developed a slight amount 

 of callus, the greater amount being formed above. No shoots were 

 formed from the callus of beeches, oaks, or laburnums. 



The production of inoculating materials (Nitragin) for use in 

 agriculture, J. A. Voelckeu {Jour. 8oc. Chem. Ind., ].'> {18!)(i), ]\'o. //, 

 pp. 7(i7-77r>. figs. 7). — The author, in a lecture before the Society of 

 Chemical Industry, gave an account of his visit to Germany, where he 

 investigated the commercial manufa(;ture of Nitragin. He also gave 

 the results of some experiments made with these inoculating nniterials. 

 The substance of the lirst i)art of his paper lias already ap()eared.' 

 In the course of his remarks i)hotomi(!rographs were shown of vari<»us 

 forms of the organisms occurring in the tubercles of different Legumi- 

 nosie. Sixteen <liflferent forms were illustrated, hwt it is stated that 

 on cultivating these organisms in gelatin or other nutritive media 

 the differences disappear and the organisms can no longer be distin- 

 guished from one another. 



Plat expeiiments Avere conducted by the author at Woburn and 

 under his supervision at two otlier jdaces in l']nglaiid. In every case 



'Jour. Roy. Afjl. Soc. Eiifrland, sor. .S, 7 (IXOtl), II, \u 2r>() (E. S. K., 7, p. iKWi). 

 175Gi— No. 10 3 



