308 BOTANICAL GAZETTE [OCTOBER 
young strobilus is one with the bract and becomes evident in the 
later stages by the comparatively rapid growth of the tissues on 
the dorsal side of the composite organ. 
In the fourth group there is no external evidence of more than 
one organ. Into this group fall Arthrotaxis selaginoides (1), 
Agathis (fig. 169), Saxegothaea (5, 8), Phyllocladus (fig. 183), 
Taxus (fig. 191), Torreya (6, 7), and Cephalotaxus (6,7). It should 
not be surprising to find forms in which the welding has taken 
place beyond the recognition of more than a single structure when 
one considers to what extent this process has taken place in Chamae- 
cyparis, Juniperus, Thuja, Cunninghamia, and Podocarpus dacry- 
dioides (4). The low cushion behind the ovule in Agathis 
australis suggests the complete fusion of a scale to a large bract; 
a similar fusion is nearing its completion in Cunninghamia 
Davidiana. 
On the basis of vascular anatomy the investigated sporophylls 
fall into two general groups. 
In the first group the bract and scale supply arises as separate 
bundles in the cylinder gap. In this group belong in general those 
forms in which the two sporophyll parts are separate and fairly 
well developed, as the seed-producing sporophylls of Pinus Kete- 
leeria, Picea, Larix, Tsuga, Pseudotsuga, and Abies (2). To this 
group belong also many in which the two sporophyll members 
present considerable to complete fusion, as Araucaria Bidwilli 
(1, 3, 10), Chamaecyparis Lawsoniana, Juniperus communis, and 
the upper sporophylls of Thuja occidentalis, Cupressus Benthamit, 
and Cryptomeria japonica. This group includes also some in which 
the sporophyll is evident only as a single organ, namely Phyllocladus 
and Cephalotaxus (6, 7). 
In Podocarpus and Dacrydium, where the strobilus consists of 
one or two sporophylls, and in Juniperus communis, the sporophylls 
receive the final bundles of the axis. There is in these instances no 
cylinder gap, and the bract and scale supplies, at least in the forms 
investigated by the writer, result from the division of one of the 
final bundles in the axis. The early division of the bundle in the 
tip of the axis perhaps justifies the placing of these forms in this 
group. 
