504 Agnes Arber.—On the Structure of the Palaeozoic Seed 
When these branches emerge into the sarcotesta they are separated by 
almost the whole width of the seed-base. They turn upwards, and pass to the 
micropyle, keeping close to the sclerotesta throughout their course. 
Localities :—South Lancashire Coalfield :—Oldham (original locality); 
Shore, Littleborough (abundant); Dulesgate; Hough Hill, Stalybridge. 
Horizon : Lower Coal Measures. 
V. The Attribution to Cordaites. 
The present investigation has thrown no fresh light on the problem— 
to what plants do seeds of the Cardiocarpus type belong ? It may, however, 
be well in conclusion briefly to review' the evidence on this point as it stands 
at present. 
In 1872 Carruthers 1 figured two species of Cardiocarpon , C . Lindleyi, 
Carr., and C. anomalum , Carr., attached to twigs, which he suggested 
belonged to an extinct Gymnosperm of the Dadoxylon type, or, as we should 
now say, to one of the Cordaitales. 
Grand’Eury 2 in 1877 pointed out that a variety of seeds known as 
Cardiocarpus are found associated with Cordaites in such a way as to render 
their identity with this genus very probable. For example, at Chazotte 
there are rocks filled exclusively with Cordaites accompanied by numerous 
Cardiocarpus seeds. Grand’Eury was also fortunately able to adduce 
more direct evidence. He found catkin-like inflorescences in actual organic 
continuity with branches bearing Cordaitean leaves, and in some cases 
these inflorescences contained seeds. The seeds varied in size in different 
specimens, and those which were best developed were recognizable as 
belonging to the cardiocarpic type. 3 
The next great advance in our knowledge of the Cordaitean fructifica¬ 
tion w r as due to Renault, 4 who in 1879 published an account of the internal 
structure of the male and female catkins, illustrated by figures which have 
now become quite familiar. 5 The female catkins were, however, much 
younger than those whose superficial features had been described by 
Grand’Eury, and were not sufficiently advanced in development to make 
it possible to identify the contained seeds with any of the numerous mature 
seeds, known only as detached specimens. 
We may conclude that the work of Carruthers, Grand’Eury, and 
Renault, has established the fact that Cordaites bore seeds of the cardio¬ 
carpic type, using the word in a broad sense. Further than this, we find 
that there is some evidence from association to show that certain species 
of Cardiocarpus are definitely connected with certain species of Cordaites. 
1 Carruthers (’ 72 ). 2 Grand’Eury (’ 77 ). 
8 e. g. the seeds of Cordaites nobilis, see Grand’Eury (’ 77 ), PI. XXVI, Fig. 9. 
4 Renault (’ 79 ). 5 Scott (’ 08 ), vol. ii, Figs. 193 and 194. 
