

violet or tilcob.olic cochinet-.l. Of these the haent'lun and 

 haenaliun v;itl: Rismark brovm .^ve tlie best results. 



file Development Lcp.if# 



Practically all tliat we knov; of tlie development of the 

 leaf in Marsilia, is due to the work of J. Hanstein, on tlic 

 leaves of tlie younr emhryo, and it v;ill he necessary to re- 

 fer to tliis often as v;e proceed. 



Tlie leaves of Marsilia arise in two rows, one on eacli 

 of the dorso-lateral surfaces of the stem. Each leaf arises 

 from one of tlie cells derived from a dorso-lateral sef<;Tnent 

 of the tetraJiedral apical cell of the stem. The leaf m.otiier 

 cell is first recorriizahle v;hen the segment in which, it a- 

 rises, is about the third or fourth in its series from the 

 apical cell. It is soon distinguished by its larger size, 

 usuall"- b^- a larrer nucleus and bv it s bulging beyoncl tl^e 

 general surface of the stem apex, (L. Figs. 1. 2. ). 



Th.e first divisio--. of the leaf mother coll, is usually 

 by a cun/-ed longitudinal anticline, appearing toward tlie 

 dorsal ed.-:o of th.e cell and with, it's concavity facin lat- 

 arally, (S. W.' Fig. 2 ). Tlie second wall is also a longi- 

 tudinal iuiticllne near the latenil edge of the moi.lier r-pii 

 and v.nth its concavity facing dorsally, (S. 7/. Fi.-. l). Iliese 



walls are also inclined to eacli otlior, (^^* •. ?.) and tl^ere 

 is thus left between them the tjq^ical two sided apical cell 



