110 



CONIFEBALES (RECENT) 



[CH. 



10 — 20 sporangia, longer and relatively narrower than in other 

 genera and attached by one end, in contrast to the more complete 

 union of sporophyll and sporangium 

 in Pinus. In Ai-aucaria Mitelleri and 

 A. Rulei (fig. 678) the microstrobili 

 reach a length of 25 cm. : in ^. excelsa 

 and A. Cookii they are much smaller 

 (fig. 679, A, B). In Taxus 4—7 spor- 

 angia are radially disposed on the 

 inner face of a flat distal expansion. 

 The microstrobili of Cunninghamia^, 

 Pseudolarix^, and Keteleeria are borne 

 in umbels, while in Cryptometia and 

 Taxodium^ they occur in spikes. The 

 microspores may be winged or wing- 

 less ; in the Abietineae there are as a 

 rule two conspicuous wings or bladders 

 (fig. 684, B), but the spores of Pseiido- 

 tsuga are wingless and in Tsuga both 

 types occur. In Microcachrys* the 

 wings vary from 2 to 6 (fig. 684, C) 

 and in Dacrydium^ and Podocarpiis^ 

 (fig. 684, A) there are 2 or 3 small 

 bladders. In Taxus, Cephalotaxus, 

 Torreya, Sciadopitys, the Cupressineae, 

 and some other Conifers there are no 

 prothallus cells : the microspores of the Abietineae are character- 

 ised by the occurrence of 2, or occasionally 3 or 4', evanescent 

 prothallus cells (fig. 684, B) ; in Dacrydium. there are 4 — 6 prothallus 

 cells ; in Microcachrys 3 or 4 ; in Podocarpus (fig. 684, A) as many 

 as 8, while in Araucaria 15 cells have been recorded and as many 

 as 30 nuclei. The two male gametes are non-motile. 



The term Conifer though appropriate as regards the majority 

 of the plants so styled is misleading in the case of several genera 



2 Boi. Mag. Jan. 1908. 



Fig. 678. Miorostrobilus of 

 Araucaria excelsa (A) and 

 Araucaria Rulei (B). (After 

 Seward and Ford ; A, nat. 

 size; B, \ nat. size.) 



1 Siebold (70) PL cni. 

 " Gard. Chron. Nov. 25, 1893, p. 659. 



« Thomson (09). ^ Young (07). 



" Jeffrey and Chrysler (07); see also Thibout (96); Burlingame (08) 

 (15); Sinnott (13). ' Hutchinson (14). 



(13); 



