226 Keegan : Results of Experiments on the Floral Colours. 



cytoplasm (Curtel, Annales des Sci. Nat. bot. ser. 8, t. 6). 

 But all the while it was held that ' every cause which slackens 

 nutrition will diminish the proportions of tannin, and conse- 

 quently those of the coloured juices which they engender.' 

 In point of fact, it was strongly suggested by my experiments 

 that the pigment was the direct result of the withdrawal of 

 the proteid substance from the corolla, i.e., the impoverishment 

 of its cytoplasm took place subsequently, and not previously. 

 This movement and withdrawal induced a process of deas- 

 similation more or less complete, a disruption of the proteid 

 molecule of the corolla cells, a separation of its nitrogenous 

 groups, and the abandonment of its aromatic groups which 

 were left behind as chromogens of pigments more or less vivid 

 and pure. This physiological action would be strictly local 

 and its principal cavise would be the powerful and insistent 

 demands which the formation and development of the pistil 

 and ovules would make upon the quantum of proteid lodged in 

 the cells of the adjacent organs, more especially the corolla. 

 When this happens to be imperative and exacting, the deas- 

 similation would be complete and a blue pigment would result ; 

 when fairly moderate, there would be a red ; when slight, it 

 would be a straw yellow or even white. The demand and 

 usufruct moreover, would be in direct proportion to the number 

 or to the size of fertile ovules produced by the pistil, and there- 

 fore it would follow that, other conditions being alike, those 

 floral organs which habitually produce most ovules ought to 

 exhibit the most vividly tinctured corollas, like what occurs 

 in the Gentians, Auriculas, Gladiolus, etc. The force necessary 

 to enlarge the ovary itself, in certain instances, so as to make 

 room for the great number of ovules produced, is also a factor 

 in the case. In cases, also, where the corolla is developed before 

 the stamens and pistils are differentiated, the drain on the 

 corolla proteid must be excessively severe, as in Mallows and 

 Hollyhocks. 



The leaflet containing particulars of ' Recent Additions, April 1910,' 

 issued by the Warrington Museum, shews a fairly extensive list of desirable 

 additions to that go-ahead institution. 



The Transactions of the Manchester Geological and Mining Society, 

 Vol. XXXI., pts. 9 and 10, contain a note on the Chew Reservoir of the 

 Ashton-under-Lyne, Staleybridge, and Dukinfield District Waterworks, 

 by Mr. A. L. Rlellor. It is accompanied by a valuable plate of sections. 



Naturalist, 



