300 PHYSIOLOGICAL BOTANY. 



that they contain cellula fibroste like other anthers. Lastly, 

 he characterises the genera Cycas, Macrozamia, Ence- 

 phalartos, and Zamia, by the form of the embryo. In an 

 appendix, vol. iv, p. 79, the formation of the albumen 

 prior to impregnation is confirmed. 



On the Plurality and Development of the Embryo in 

 the Seeds of Conifers. By ROBERT BROWN. Annals of 

 Natur. History, vol. xiii, p. 369. This paper was read 

 before the British Association at Edinburgh in 1834 ; it 

 was published in French in the ' Annal. d. Scienc. Natur/ 

 for October 1843, and then appeared in the above journal. 

 After alluding to his former views upon the plurality of 

 the embryos in the Cycadese, which indicates their affinity 

 with the Coniferse, the author then reports upon his 

 observations on the seeds of Pinus sylvestris. " The first 

 and most important change," says he, " is the production 

 or separation of a distinct body within the nucleus of the 

 ovule, which before impregnation is a solid uniform sub- 

 stance. In this stage, the included body or amnios is 

 slightly concave, and covered with a lacerated cellular 

 tissue, which either arises from its separation from the 

 apex of the original nucleus, or of a process which con- 

 nects it to the apex. Below the concave apex, the amnios 

 is slightly transparent for about one fourth of its length, 

 the remaining portion being perfectly opaque ; it consists 

 of cellular tissue. Before the appearance of the embryos 

 or the funiculi, the areolse in which they are produced are 

 visible. These areolse, three or five in number, as ob- 

 served in May 1827 in the larch, are arranged in a cir- 

 cular or elliptical series, near the apex, with which they 

 probably communicate by some points which it is difficult 

 to distinguish. In Pinus sylvestris^ they were consider- 

 ably more developed in June or July, from four to six in 

 number, consisted of conical membranes of a brown colour, 

 with their apices turned towards the surface, and at the 

 base seeming to pass gradually into the lighter-coloured 

 pulpy mass of the amnios. Corresponding and nearly 



