PLATE 34 



A. — Lemon seedlings, i6 days old, grown in distilled water as control. 



B. — Lemon seedlings, i6 days old, grown in 400 parts per million sodium carbonate. 



C. — Lemon seedlings, 16 days old, grown in 100 parts per million ammonia-soluble 

 humus. 



D. — Lemon seedlings, 16 days old, grown in 100 parts per million ammonia-soluble 

 humus plus 400 parts per million sodium carbonate. 



E.— Citrus seedlings grown in carbon-treated water. 



F. — Citrus seedlings grown in 4/10 per cent so'dium nitrate (NaNOg). 



G. — Citrus seedlings grown in 4/10 per cent sodium nitrate with calcium carbonate 

 (CaCOs). 



