ON STAINING SECTIONS WITH MAGENTA. 139 



were furnished only in part by the reserve-stuff from the 

 spores, and thus of course for the other part were produced 

 at the cost of the organic nutriment from the algae involved ; 

 in other words, the ocerminatini; filaments and their branches 

 had continued to grow parasitically when once in contact 

 with the algae. 



Though I have then not yet succeeded in producing a 

 perfect heteromerous lichen-thallus from its component ele- 

 ments, I still think I am perfectly justified in affirming that 

 the results of my cultures are alone explicable by assuming 

 the double nature of lichens ; so that from the upholders of 

 the organic individuality of the heteromerous lichens all 

 arguments in its affirmation are equally taken away in an 

 experimental way as has been previously done by Schwen- 

 dener in an anatomical way." 



On Staining Sections with Magenta. By W. Hatchett 

 Jackson, B.A., Oxon., F.L.S. 



Staining with magenta has its advantages and dis- 

 advantages. Like the ammoniacal solution of carmine, 

 magenta stains all parts of a tissue indifferently, but, unlike 

 carmine so used, it gives (as far as my experience goes) a 

 much greater depth and gradation of colour. When a thick 

 section is stained with carmine the tint given is so uniform 

 as to be but little help towards deciphering the complex 

 structure, but with magenta the various parts generally 

 assume such different tints that this is not the case. 



On the other hand, magenta does not answer well when a 

 tissue has got rather a dark greenish colour from long soaking 

 in chromic acid, nor is the staining once done permanent. 

 This want of permanency seems to me to be due to two 

 causes — either the colour soaks out into the preservative 

 medium, or a salt of magenta (triacid) is formed by decompo- 

 sition, especially in the presence of light. 



Some time, more than a year, ago it was suggested to me 

 by a friend that it would be a good thing if some method of 

 preserving magenta-stained specimens could be discovered. 

 Accordingly I set to work, and after some trouble have hit 

 on a process which, perhaps, may be found of service. The 

 considerations which have led me to adopt it are the 

 following : 



Rosaniline, or magenta, is a triamine, and therefore with 



