MISCELLANY, 



765 



but, on the contrary, may be produced at a 

 single leap, the author draws the following 

 conclusions : 



1. Morphological changes in individual 

 plants are not always by gradual modifica- 

 tions. 2. Yariations from specific forms 

 follow the same law. 3. Variations are 

 often sudden, and also of such decided 

 character as to seem generic. 4. These 

 sudden formations perpetuate themselves 

 similarly in all respects to forms springing 

 from gradual modifications. 5. Variations 

 of similar character occur in widely-sepa- 

 rated localities. 6. Variations occur in 

 communities of plants simultaneously by 

 conditions affecting nutrition, and perhaps 

 by other causes. From these premises Mr. 

 Meehan argues that new and widely-dis- 

 tinct species may be suddenly evolved from 

 preexisting forms without the intervention 

 of natural selection, and, of course, without 

 the existence of connecting links. 



Many who heard this paper were at first 

 disposed to consider it an attack on Dar- 

 winism, its tendency being to lessen the 

 importance of the principle of natural se- 

 lection. But its discussion showed that 

 such was not the view of those best able to 

 judge ; Profs. Morse, Riley, Gill, Gray, and 

 even Mr. Meehan himself, regarded the ar- 

 gument as a contribution to the theory of 

 evolution, while all but the author were of 

 the opinion that it was quite consistent 

 with the principle of natural selection, and, 

 indeed, had already been taken into the ac- 

 count by Mr. Darwin. 



Mtrogen of the Soil. — Prof. H. B. 

 Armsby read at the American Association 

 meeting a paper on the " Nitrogen of the 

 Soil," in which, after stating that no plant 

 has the power, so far as we know, of taking 

 its nitrogenous materials directly from the 

 atmosphere, he investigates the sources from 

 which the nitrogen of plants is derived. 

 Nitrogenous organic substances, such as 

 exist in freshly-manured soils, may yield 

 free nitrogen by decomposition, though the 

 particulars of the process are as yet not 

 fully ascertained. Under some circum- 

 stances these organic substances are capa- 

 ble of causing free nitrogen so to enter into 

 combination with them as to increase their 

 nitrogenous contents. This increase has 



generally been attributed to the formation 

 of nitric acid from free nitrogen by oxida- 

 tion. The author made a series of experi- 

 ments on the loss and gain of nitrogen, his 

 method being to allow organic matter con- 

 taining a known amount of nitrogen to de- 

 cay, under circumstances allowing measure- 

 ment of the nitrogen given off or accumu- 

 lated. The organic matter consisted of 

 dried and sifted barn-yard manure, mixed 

 with one-quarter its weight of dried and 

 pulverized flesh. There were eight experi- 

 ments in all, four of which were conducted 

 in purified air, and four in purified nitrogen. 

 The quantities and materials used for the 

 two series of experiments were as follows : 



II. 



The result of the experiments shows a 

 loss of nitrogen in Nos. 1, 3, and 4 of Series 

 I., amounting to 11.11, 6.21, and 13.09 per 

 cent, respectively ; and in Nos. 3 and 4, of 

 Series II., of 1.14 and 1.94 per cent. No. 



2, of Series I., shows a gain of 15.22 per 

 cent. ; and Nos. 1 and 2, of Series II., a gain 

 of 1.48 and 19.34 per cent, respectively. 

 The author's conclusions are: 1. The loss 

 of free nitrogen during the decomposition 

 of nitrogenous organic matter is generally 

 due to oxidizing action. 2. An increase 

 of combined nitrogen in soil may take place 

 by oxidation of free nitrogen to nitric acid. 



3. Some organic substances in the presence 

 of a caustic alkali are able to fix free nitro- 

 gen without the agency of oxygen, or the 

 formation of nitric acid. 



Tea-Production in Bengal, British In- 

 dia. — In the entire presidency about 800,- 

 000 acres are "held for purposes connected 

 with the tea-industry." Of this only about 

 '70,000 acres are occupied with tea-plants 

 in bearing. This portion is subdivided 



