32 



EDWARD C. JEFFREY ON 



The results of the present investigation seem only to add confirmation to this view. 

 Although the reproductive apparatus of the Cordaites, as far as we are at present 

 acquainted with it, was somewhat different in its organization from that of the Conifer- 

 ales, still as Dr. Scott (:00) has pointed out in the case of the female axis, it is not diffi- 

 cult to trace homologies with that of the latter group, if we regard the ovuliferous 

 apparatus in the Conifers as consisting of a reduced and modified axillary shoot. The 

 anatomical study of the vegetative organs of the Coniferales, as represented in the pres- 

 ent instance by the Abietineae, serves strongly to confirm the relationship of the two 

 groups. It seems quite impossible to refer the Coniferales any longer to a Lycopodineous 

 ancestry, although their superficial features seem somewhat to favor such a derivation. 

 It has been pointed out by the writer (:02) that the mode of exit of the leaf trace from 

 the central cylinder, even in those Conifers which have their foliage most reduced, is 

 distinctly Filicinean, and of a type which is never found in the Lycopods or their allies. 

 The present research increases the difficulty of the Lycopodineous phylogeny, by making 

 clear that the foliar fibro vascular supply in the case of the Abietineae is of the same double 

 type as that which is primitive for the Lyginodendreae, the Cordaitales, the Cycadales, 

 the Ginkgoales, and many Filicales. 



Summary. 



1. The Abietineae are divisible, on the evidence supplied by a study of their vegeta- 

 tive and reproductive organs, into two very distinct subfamilies, viz., the Pineae and the 

 Abieteae. 



2. The Pineae are characterized by the invariable presence of resin canals, forming 

 an anastomosing system in the secondary wood and cortex of root and shoot. Resin 

 canals are present in the outer margin of the primary wood of the root. The scales of 

 the female cone are not deciduous. Pinus, Picea, Larix, Pseudotsuga. 



3. The Abieteae ordinarily do not possess resin canals in the secondary wood of 

 root and shoot. Resin canals, however, are sometimes found in the wood of the female 

 reproductive axis, and in the first annual ring of vigorous shoots of sexually mature trees. 

 Resin canals occur in the secondary wood in tangential rows, as a result of injury. Resin 

 canals are invariably found in the center of the primary wood of the root. The scales of 

 the female cone are generally deciduous. Abies, Pseudolarix, Cedrus, Tsuga. 



4. The evidence derived from anatomy and experimental morphology goes to show 

 that the presence of resin ducts in the woody tissues and in the cortex of the Abietineae 

 is primitive for the group. The resin canals persist longest in the reproductive axis, the 

 leaf, and the first annual ring of root and shoot. In the more specialized genera 

 the resin canals of the wood are replaced by resin cells, but in the latter condition 



