Linnean Society of London. 171 



four of the sections passed. In the two terminal sections of this 



series the spiral coil was clearly shown, consisting of about 



three windings. The spiral is connected with the nucleus of the 



cell, but whether it is itself of niiclear or cytoplasmic origin is 

 not certain. 



In the preparation frora Cycas revoluta, several pairs of 

 generative cells were shown ; in some cases the pollen-tube en- 

 closing them was intact. The spiral coils in some of the generative 

 cells were surprisingly clear, consisting of about four windings. 

 A distinct striation was visible in connection with the coil, pro- 

 bably indicating the presence of the numerous cilia described by 

 the Japanese discoverers. 



The facts admit of no other interpretation than that given 

 by these authors, namely that in both Ginkgo and Cycas each 

 generative cell gives rise to a spiral spermatozoid; the latter 

 by its own movements (actually observed by Dr. Hirase in the 

 case of Ginkgo) no doubt travels from the end of the pollen-tube 

 to the female cell. 



In a discussion which followed on this highly important sub- 

 ject, Dr. W. T. Thiselton Dyer, Mr. W. Carruthers, 

 Prof. E. Ray Lankester, Prof. Howes, and the President 

 took part. 



M. Miller Cliristy read a paper on y^Primula elatior .Jacq., 

 in Britain." He remarked that this widely-distributed continental 

 plant, though figured accidentally in „English Botany" in 1799, 

 was not really detected in Britain tili 1842, to which time the 

 totally distinct hybrid Oxlip (P. acaulis X veris) was, by British 

 botanists, confused with, and mistaken for it, as is still frequently 

 the case. In Britain, P. elatior occupies a sharply defined area, 

 divided by the Valley of the Cam, with only two outlying loca- 

 lities, so far as Mr. Christy could ascertain. This area covers 

 the two most elevated and unbroken portions of the river-valleys 

 and the Chalk being entirely avoided. The boundary-lines 

 (some 175 miles in length) which had been traced by Mr. 

 Christy with precision Avere, in consequence, very sinuous. 

 They enclosed together about 470 Square miles, over which area 

 the Oxlip flourishes in immense abundance in all old woods and 

 some meadows ; while the Primrose (which grows all around) is 

 entirely absent. Along the dividing line between the two, which 

 is very scharply defined, hybrids are produced in great abun- 

 dance. On the other band, the Cowslip (which grows both around 

 and throughout the Oxlip-area) very rarely hybridizes with it. 

 Mr. Christy believed that the Primrose was, in this country, 

 gradually hybridizing the Oxlip out of existence. He then noticed 

 a rare single-llowered variety of P. elatior, which he proposed 

 to call var acaulis^ and several aberrations, showing upon the 

 screen photographic views of these and of the hybrids, as well 

 as a map of the distribution of the Oxlip in Britain. 



