540 GYMNOSPERMAE 



they are guided to the left or right on the margins of the latter. Corresponding to 

 this mechanism the pollen-catching process of the ovule is unilateral, and forming 

 a broad lobe directed up- and inwards, and curved in like a helmet, in which the 

 pollen-grains sliding down the side of the scale must fall. After pollination the cones 

 remain vertical. Kerner states that the anthers of the male flowers dehisce in the 

 same way as those of the pines. Warnstorf (Schr. natw. Ver., Wernigerode, xi, 1896) 

 describes the pollen-grains as pale-yellow in colour, hemispherical, smooth, 75-87 /u, 

 in diameter. 



1035. Abies L. 



3104. A. pectinata DC. (= A. alha Mill., Pinus Picea Z., and T . Ahks Burot). 

 (Strasburger, op. cit., p. 255.) — This species is monoecious. The pollination 

 mechanism closely resembles that of the larch ; here again the guiding of the pollen 

 is performed by the carpels. These are provided with a long keel, while the small, 

 fleshy ovuliferous scales remain concealed in the axils of the carpels. There is also 

 a similar unilateral galeate lobe to each ovule for catching the pollen-grains. After 

 pollination the cones remain vertical. 



3105. A. balsamea Mill. (= Pinus balsamea Z.). — This species possesses 

 a similar pollen mechanism to those of larch and silver firs, according to Richard 

 (' Commentatio botanica de Conifer, et Cycad.,' 1826). 



1036. Thuya L. 



3106. T. orientalis L., and 3107. T. occidentalis L. (Strasburger, op. cit., 

 p. 256.) — These and other species possess a similar mechanism to that of the larch. 

 The young female flowers are vertical, and the ovules are situated fairly deeply 

 between the ovuliferous scales, but the micropyle always projects so far during 

 anthesis that the pollen-grains can easily fall upon it, or can be guided to it by the 

 scales. 



1037. Oxycedrus Hart. (= Juniperus Tourn., according to the Index Kewensis). 

 Similar to Larix. 



1038. Callitris Vent. 



3108. C. quadrivalvis Vent. — This species resembles Thuya. 



1039. Dacrydium Soland. ; 1040. PhyllocladusRich.; 1041. TorreyaAm., 

 1042. Cephalotaxus Sleb. et Zucc. ; 1043. Saxegothaea Lindl. ; and 



1044. Podocarpus Pers. 



Species of these genera most closely resemble Taxus and Ginkgo (Salisburia). 

 (Strasburger, op. cit.) 



1045. Cupressus Tourn. 



Similar to Thuya. 



3109. C. sempervirens L. (Strasburger, op. cit., pp. 256-7.) — In this species 

 the cone is formed by a large number of decussate ovuliferous scales, at the base of 



