360 



THE AMERICAN NATURALIST H'ol. XLI 



ven^ badly preserved. Dacrydiiim is distinguished from Podo- 

 carpus by the transverse striations of the thickened posterior wall 

 of its microspore. In the species of Dacrydium which we have 

 examined more than two prothallial cells are present, but the 

 derivatives of the prothallial rudiments do not seem to be as 

 numerous as they are in Podocarpus, where there may apparently 

 be as many as eight present (P. ferruginea). 



Through the kindness of Dr. Cockaviie ha\e had the op- 

 portunity of comparing the microganiet()])liyTic (lc\el<)pment of 

 Podocarpus and Dacrydium with that ])reseiit(Ml in Agathis, 

 probably the more ancient of the two living genera of the Arau- 



natelv verv much shrunken, possiblv on^accolmt of the small 

 amount of alcohol m which it was preserved, but this fortunatelv 

 does not interfere with the understanding of the general conditions 

 present in the microgametophvte. In h figure 5. is shown an 

 apparentlv mature microspore, ^^e cannot however speak with 

 certaintv on this point, since none of the microsporophvlls in our 

 possession have shed their pollen. It is to l)e noted that the 

 conditions present in this figure closelv reseml)le those depicted 

 in h figure 2. and d figure 3. In other words there are sub- 

 M(|utnt uituhnil(h\i lonsprt < nt m tlu two pi .tli ilU il in Imunts 

 which an <ru..idb 1 u<l dmn tlu n ik u. tlu Vbittnu . 1 

 figure rcscinl>h's ch.sdv and dilVcrs in tlic fact that onlv one 

 of the piothilliil I ihncM 1 . 1( n< hM 1< 1 In < figuie 5, 

 1^ ^ho^^n a tuu 1 ti i! \ < \ t i t tl < i . tl illi il ( t lU Ihere 



