Messrs Gardiner and Hill, Histology of the Endosperm. 445 



The Histology of the Endosperm during Germination in Tamus 

 communis and Galium Tricorne. By Walter Gardiner, M.A., 

 F.R.S., Fellow and Bursar of Clare College, and Arthur W. Hill, 

 M.A., Fellow of King's College. 



[Bead 17 February, Received 12 June 1902.] 



In a communication laid before the Royal Society in 1897 l , 

 a description was given of the phenomena which accompany 

 germination in the Endosperm of Tamus communis. We have 

 recently re-examined the endosperm of Tamus and also investigated 

 the histology of the endosperm of Galium Tricorne by way of 

 comparison, and we hope to study the germination of other thick- 

 walled seeds in the same way as opportunity occurs. 



The macroscopic features of the germination of Tamus prove to 

 be of some interest, and as only a few figures of the stages of 

 germination have been published before by Bucherer and others 2 , 

 it seems well to describe shortly the external features of ger- 

 mination before proceeding to consider the changes which take 

 place in the endosperm. If one of the small, round, seeds be 

 examined the micropyle can be distinguished as a tiny brown 

 point. Beneath it is situated the somewhat ovoid embryo, which 

 is found to be lying in a radial position, with its more pointed or 

 cotyledonary end directed towards the centre of the seed, and its 

 blunt end, which is occupied by the radicle, lying just internal to 

 the micropyle 3 (Plate V, Fig. 3). In a thin section through the 

 micropyle the actual pore is visible, surrounded by the strongly- 

 thickened and suberized walls of the integuments. 



On the commencement of germination, the radicle begins to 

 grow outwards and, owing to pressure from within, a little semi- 

 circular area of the testa around the micropyle breaks away from 

 the rest of the seed coat and gets pushed upwards by the emerging 

 radicle ; and since at one point it remains attached to the seed 

 coat, it has the appearance of a little lid having the peg-like 

 micropyle in the centre (Fig. 1). Through the opening so formed 

 the radicle grows out (Fig. 2), followed soon afterwards by the 



1 Gardiner, W., Proc. Roy. Soc, 1897, p. 105, figs. 1 and 3. 



2 Bucherer, Bibliotheca Botanica, Heft 16, Le Maout and Decaisne (Eng. ed.), 

 pp. 794, 795. 



3 Cf. Solms Laubach, Bot. Zeit., 1878, pp. 65—82. 



