1893.] Presents. 337 



similar weights taken from the same original packets were similarly 

 sown as controls. 



The table on p. 336 gives the results of one such series of experi- 

 ments, where the exhaustion of the tubes was kindly undertaken by 

 Mr. Crookes, F.R.S., to whom I must express my best thanks for the 

 assistance he has given. But it may be mentioned that other series 

 of experiments yielded virtually the same results. 



With the exception of the beans, where only two were sown, ten 

 weighed seeds were sown out of each of the tubes, and also out of 

 each of the control packets which had been kept in ordinary air 

 from the first. These results amply prove that neither a vacuum 

 of one-millionth of an atmosphere, nor the atmospheres of any of 

 the gases and vapours named in the above list, exercised much, if 

 any, effect on the germinating power of any of these seeds. I may 

 add that the same remark applies to an atmosphere of carbon di- 

 oxide, although in the particular series of experiments quoted this 

 gas was accidentally omitted. 



A subsidiary object of these experiments was to ascertain whether 

 any appreciable variations would be caused in plants grown from 

 seeds which, before germination, had been submittted to the condi- 

 tions above explained. Hundreds of plants of the kinds named in 

 the above table were grown from the seeds in 'the various tubes. 

 But in no one instance was there the smallest deviation in any 

 respect from the standard type grown from the corresponding con- 

 trol packet. 



It will be observed that, in the case of the beet-root, a larger 

 number of plants were developed in many of the pots than the ten 

 seeds which had been sown in each. This I found to be due to the 

 fact that beet-root seeds very frequently throw up two seedlings apiece. 

 Not so frequently, but still very often, they yield three, and some- 

 times even four. 



Further experiments are in progress. 



Presents, November 16, 1893. 

 Transactions. 



Adelaide : Royal Society of South Australia. Transactions. 

 Vol. XVI. Part 2. Vol. XVII. Part. 1. 8vo. Adelaide 

 1893. The Society. 



Albany, N. Y. : Albany Institute. Transactions. Vol. XII. 8vo. 

 Albany 1893. The Institute. 



Amsterdam : Koninklijke Akadeniie van Wetenschappen. Ver- 

 handelingen. Eerste Sectie. Deel I. Tweede Sectie. Deel 

 1 II. 8vo. Amsterdam 1893 ; Verslagen en Mededeelingen. 

 Afd. Naturkunde. Deel IX. 8vo. Amsterdam 1892. Regis- 



