Endosperm of Hordeum vulgare during Germination. 5 



which was followed the year afterwards by a more detailed paper 

 on the same subject by Hansteen himself.* 



Hansteen strenuously opposes Van Tieghem's division of endo- 

 sperms into "active" and "inactive," and asserts that the latter 

 was led into error on this point by not taking precautions to put 

 his endosperms under conditions favourable for the rapid removal of 

 the products of change. Although reference is made to the Brown 

 and Morris paper of 1890, the author does not appear to have made 

 himself thoroughly acquainted either with the details of the experi- 

 ments described or with the conclusions drawn from them. 



Hansteen's principal experiments were made with the seeds of Zea 

 Mays and Hordeum vulgare, but he also made observations on the 

 mucilaginous endosperm of Tetragonolobus purpureus, and the cotyle- 

 dons of Lupinus luteus and Helianthus annuus. For our present pur- 

 poses it is only necessary to consider the experiments on barley and 

 maize. The seed was, in the first instance, soaked in water for two 

 days, and the embryos, including the scutellum, were removed. To 

 the isolated endosperms there was then applied a mixture of plaster 

 of Paris and water, so as to form a small plaster column, which 

 occupied the original position of the embryo. 



The little plaster columns, with the endosperms attached, were 

 then put into glass dishes containing a sufficient amount of water 

 to reach half-way up the columns. In order to avoid the disturbing 

 influence of micro-organisms the seeds were placed for two hours in 

 a 1 per cent, solution of copper sulphate ; all the materials and 

 vessels used were carefully sterilised, and the experiments were 

 performed under strict antiseptic conditions in a cultivation chamber 

 so arranged as only to admit germ-free air. The author states that 

 he has been able in this manner to maintain his cultures sterile for 

 at least a month. When there was a sufficient amonnt of water in 

 the culture- dishes, and the conditions were thus favourable for a 

 rapid outward diffusion of the products of change, Hansteen found 

 that, within from ten to thirteen days of commencing the experi- 

 ment, the isolated endosperms of both maize and barley had given 

 rise to a very considerable self-digestion of the cell-contents. In 

 the immediate neighbourhood of the plaster the cells had quite lost 

 their starch, whilst the starch-granules, even at a distance, were 

 more or less corroded, and the partially depleted endosperm had 

 become soft and disintegrated. ]n the case of barley these visible 

 changes were very strongly marked indeed, and simultaneously with 

 them sugar could be detected in the water into which the small 

 plaster columns dipped. 



In those experiments in which the amount of water had been 

 much reduced, but very little starch-erosion took place at the point 

 * ' Flora,' vol. 70, 1894, p. 410. 



