92 Gelehrte Gesellschaften. 



If the protoplasm were outside it is equally obvious it would bear 

 out my interpretation. I can prove that this is so'. 



As I had no theory either to defend or to combat, I sought 

 simply to determine the nature of the bodies by independent and 

 reliable tests, and these have led me to the conclusion formerly stated 

 by me, that the protoplasm forms a mass within the Oxalate of lime, 

 though probably the latter is partially embedded in, and not merely 

 adherent to, the surface of the protoplasm. This conclusion is based 

 upon the following reasous: — The protoplasmic residuum is so con- 

 siderable after removal of the Oxalate, that if it formed a coat outside 

 the latter, as Mr. Murray supposes it does , it would be visible 

 along the edges of the body without requiring the use of iodine. 

 Again , were it merely part of the contents of the Potato-leaf cell, 

 accidentally adhering to the mineral mass, we could scarcely suppose 

 that the outline of such protoplasm would continue so definite, not 

 showing any tendency to dissolve in the surrounding fluid ; and, were 

 the protoplasm such a mere coat, it would surely be possible, after 

 Solution of the Oxalate, to detect the cavity in which the latter lay ; 

 but in the numerous bodies that I have examined carefully under 

 varied conditions no such appearance has ever presented itself. The 

 changes produced by nitric acid, and the appearance of the body after 

 it has ceased to act, are admirably exhibited in Mr. W. G. Smith 's 

 figures published last year in the Gardeners' Chronicle, Dec. 13, 1884. 



In reference to Mr. Murray's experiment of using iodine to 

 demonstrate the external protoplasm on a ,sclerotiet' which has been 

 isolated merely, without Solution of the Oxalate, it is only what might 

 be expected, that a ,delicate colouring' should be observed , due in 

 part probably to the protoplasm irabedding the inner ends of the 

 particles of the Oxalate, and in part, it may be, to a little of the 

 Contents of leaf-cells (of which many are necessarily torn in dissecting 

 out the bodies) adhering to the surface. 



As to the internal structure of the uninjured ,sclerotiet' and its 

 behaviour with iodine internally I am ignorant , simply because the 

 bodies are absolutely opaque while uninjured , except along the extre- 

 mely uarrow margin. I cannot see that Mr. Murray's test in any 

 way throws light in the direction indicated by him. There seems no 

 cause for regret that the nature of the ,sclerotiets' is being fully 

 discussed, even were it the case that ,a deal of trouble might have 

 been saved , but for the assertion that the Oxalate of lime contained 

 a central mass of protoplasm'. In regard, to what may be called the 

 historical side of Mr. Murray's report it is undoubtedly of interest 

 to those even who do not find themselves able to accept it as decisive. 

 Before it could be held that ,sclerotiets' are ,iutrinsic products of the 

 Potato plant' it must surely be proved that they are of still greater 

 constancy than any evidence yet Warrants us to assume, Systematic 

 and extended inguiries by Mr. Murray and others, so situated as to 

 be able like him to pursue them , cannot fail to be of much value. 

 Another line of investigation worth working, would be the examination 

 of Tomatos and any other plants attacked by Phytophthora infestans, 



