CONIFERALES 



295 



branch in the axil of the bract; it has been called an open carpel, a 

 placenta, a ligule, the blended integuments of two ovules; it has 

 been called a leaf of an axillary shoot, the first two leaves of an axil- 

 lary shoot fused by their margins; and if any possible structures 

 have been omitted from this list, it may be assumed that someone 

 has applied them to the ovule-bearing structure. Worsdell,7°7 in 

 1900, collected and discussed the 

 literature, and practically nothing 

 has been added since. 



In all of the investigations and 

 philosophizing great stress has 

 been laid upon abnormal cones, 

 where various intergrades between 

 reproductive and vegetative struc- 

 tures have been found. Nearly all 

 of these abnormal cones have been 

 studied only in the mature condi- 

 tion. Since trees which produce 

 abnormal cones produce them year 

 after year, material of young stages 

 could be collected, and it would be 

 interesting to make a comparative 

 study of the development of such 



Fig. 300. — Finns banksiana: part of 

 young ovulate cone, showing bract {b), 

 with the "ovuliferous scale" (5), in its 

 axis; X350. 



cones throughout the order, com- 

 paring especially the cones of forms 

 with and without spur shoots; 

 and comparing those with bract 

 and ovuliferous scale free, as in Abietaceae and Podocarpaceae, with 

 those which have the bract and ovuKferous scale "fused," as in 

 Taxodiaceae and Cupressaceae. On account of the peculiar relations 

 of the ovuliferous structures, a study of young proliferating cones in 

 Araucariaceae should be particularly interesting. A comparative 

 study of young stages in the ovuliferous structures of the Taxares — 

 Podocarpaceae and Taxaceae — ^would also be valuable, since it might 

 reveal the presence of lost structures, the absence of which started 

 the designation of "conifers without cones." 



For many botanists, any structure in the axil of a leaf must be a 



