160 ACTION OF AMMONIUM MOLYBDATE, ETC., 



deeply versed in phytological lore, may yet thereby find employ- 

 ment and scope for their energies, and at the same time furnish 

 materials for the higher-trained botanist to work out. 



The following is a summary of results. Of about 120 genera 

 examined, 34 yield no results under the action of Ammonium 

 Molybdate, either alone or followed by Potassium Sulpho-Cyanide. 

 This furnishes a fair per centage, indicating some decided chemi- 

 cal difference in the plants experimented on : — 



34, none. 



15, partial. 



71, complete. 



120. 



This subject of investigation is a large one, and will require 

 the co-operation of many workers, spread over several seasons, 

 before reliable results can be obtained as to any ordinal or generic 

 value of these reactions. Whole families appear to be acted on, 

 as the Myrtacece. and Proteacece^ while others exhibit breaks. The 

 Monocotyledons, I suspect, will prove to be little affected. 



I have arranged the plants I have examined in some general 

 related form, but I think it well to indicate what plants will best 

 and most readily illustrate the matters of this paper : — Robinia, or 

 False Acacia, Peach, Eucalyptus^ Xanthium or Bathurst Burr, 

 Ceanothus^ Loquats, Walnut, Schinus or Pepper-Tree, Jasmine, 

 Honeysuckle, Morton Bay Fig. The deciduous stipule (?) or 

 bract overtopping the early form of the leaves exhibits the latex 

 vessels very beautifully coloured by the reagent, as also the petiole 

 and cells of the leaf proper. 



I prepare the Ammonium Molybdate solution by saturating 

 the Molybdic Acid with Liquor Ammonise, and allowing any 

 free Ammonia to evaporate. The solution can be diluted freely. 

 In some cases, the slightest portion of it on a slide, or on the 

 finger, reacts before one is aware of it, as may happen when many 

 specimens are examined at one sitting. 



Table of Genera Examined, 

 acotyledons. 



Filices. 

 o Pteris umbrosa, } 

 o Adiantum cethiopium. 



X Polypodium Billardieri. 



X Lomaria, sp. 



X Todea rivularis, ? 



