CONIFERALES 



301 



as an integument. It can be distinguished at the time of pollination, 

 and, in late stages, becomes red and fleshy, giving the seed its berry- 

 like appearance. 



In the Podocarpaceae the epimatium is a striking feature of the 

 ovule (fig. 306). It starts like an integument and looks Uke one. 

 Below it, is the receptacle, which be- 

 comes very large and fleshy. The 

 aril of Taxus and the outer fleshy 

 covering in Torreya start in the same 

 way. In Gnetum a delayed integument 

 also starts in this way. Some regard 

 all of these structures as tegumentary 



Fig. 305. — Dacrydiiim elatiim: A, tip of 

 twig with ovuliferous structures covered by 

 leaves; B, the same with leaves dissected 

 away, showing two leaves, each bearing an 

 ovule on its inner (adaxial) face; X6. — 

 After Hagerup."* 



Fig. 306. — Podocarpus: ovule and 

 epimatium. The female gametophyte 

 in an early free nuclear stage, e, 

 epimatium; r, receptacle; X 10. 



in their origin, but the epimatium may be homologous with the ovu- 

 liferous scale, rather than with the integument. 



The megaspore. — In many cases the megaspore mother-cell be- 

 comes recognizable so late in the development of the ovule, and is so 

 deeply placed, that it is impossible to determine just what the origin 

 may have been (fig. 307 £). In a species like Pinus, where the mega- 

 spore mother-cell is so deeply placed, one can imagine a row of cells 

 from a hypodermal cell down to the mother-cell. Wherever the ori- 



