234 MR. S. LE M. MOOEE'S STUDIES 



worth mention is the great difficulty met with in peptonizing the 

 paracallus : this I suppose due to the fact that the spirit in 

 which the material was kept was found, upon examination, to 

 have evaporated, so that upon the dehydration undergone from 

 the action of the spirit desiccation had supervened ; and this might 

 well tend to make the paracallus less soluble. Anyhow, be the 

 reason what it may, I now found it impossible to entirely dissolve 

 the paracallus in a peptic fluid; and although a pancreatic fluid 

 was more efficient, it failed in a few cases. This should teach 

 caution in the attempt to classify these proteids upon results 

 yielded by preserved material : for this reason I wish it to be 

 understood that the comparison between the substance of Ballia 

 stoppers and lardacein, drawn in the former memoir, is to be 

 regarded as merely provisional. 



That an undoubted proteid should, apparently because of the 

 dense aggregation of its particles, refuse to answer to those di- 

 stinctive proteid tests — the taking up of aniline-blue and of 

 carmine — is a singular fact ; it is very often the case with the 

 typical paracallus studied by me. Another seeming consequence 

 of this density is the peculiar appearance borne by some sieves 

 ("hedgehog" sieves they might be called) of desiccated Vegetable- 

 Marrow material : the meshes of these sieves are blocked up 

 with the hard paracallus which in surface-view projects therefrom 

 in the form of a number of hard bristly points (PL XXV. fig. 7) ; 



* 



an 



peptonizing fluid. 



The Ash. 



This is a good type to study, on account of the great deve- 

 lopment of its callus : the obliterated sieves are shown, PI. XXV. 



or 



o 



figs. 2 and 4a. Occasionally one may find a few sieves open durin 

 the winter ; but for the most part they are blocked up with oval 

 masses of callus presenting the normal reactions. I have not 

 found paracallus on any of these sieves. 



After many experiments, no encouragement has been given to 

 the idea that this callus may yield proteid reactions; all the 

 masses behave exactly as do those of the abaxial tubes of the 

 Fig. Moreover, the callus resists both gastric and pancreatic 



digestion. 



The Dog-Rose. 



Most of the sieves of one-year shoots of Eosa canina are, during 



