170 The Anatomy of Plants BOOKII 



studied both animals and plants, Heitzmann's observations 

 were confined to the former. 



If we occupy ourselves mainly with the work of botanists 

 we find among them many cordial supporters of the reticular 

 theory. Foremost among them stood Strasburger, who in 

 1876 held the structure to be a net-like substance, with 

 coarse vacuolation ; he distinguished between the intra- 

 protoplasmic vacuoles and those larger chambers in the 

 cell which are now commonly known by the same name, 

 and which are distinct, of larger size, and filled with an 

 albuminous sap. 



Schmitz in 1880 carried the theory a little farther. 

 Working on material that had been fixed with picric acid, 

 he held that his preparations justified him in speaking not 

 only of a reticular structure, but of a limiting layer on 

 its exterior or its free surfaces. This he described as con- 

 stituted by a narrowing, or in some cases by an obliteration, 

 of the meshes of the framework in these positions. The 

 granular punctations visible in the protoplasm he attributed 

 to the nodal points of the network. 



Important contributions to the knowledge of the subject 

 were made in 1881 and 1882 by Reinke and Rodewald as 

 the result of researches on the plasmodia of Aethalium. 

 In this organism they found a firm ground substance, 

 holding in a kind of spongy framework a fluid which they 

 called the enchylema. The latter could be driven out by 

 pressure, leaving the framework as a hard cake. They 

 believed the framework to be of a plastic and contractile 

 nature, to be permeated by the albuminous enchylema, 

 and to be shut off from the exterior by a thin layer of its 

 substance specially differentiated for that purpose. They 

 were inclined to hold the arrangement of the material or 

 substance of the framework to be alveolar. 



Schwarz's work of 1887, to which reference has been 

 made, was an attempt to reconcile the filamentous or 



