Literary Notices. xxv 



We miss from the bibliography reference to Nansen, whose his- 

 tological studies certainly should be consulted in any study of crusta- 

 cean neuro-histology. 



Invertebrate neurology owes thanks to our veteran entomologist 

 for the valuable work before us. 



The Connective Tissue Skeleton of the Spinal Cord. 1 



Sections of the spinal cord hardened in Miiller's fluid and stained 

 with acetic hematoxylin and afterwards differentiated with Weigert's 

 borax-ferricyanide of potassium in very dilute solution, exhibit super- 

 ficially a very sharp differentiation between gelatinous connective tis- 

 sue and neuroglia. 



The gray cortical layer of the cord and the septa passing from it 

 inward consist of a tissue which is sharply distinguishable from gela- 

 tinous connective tissue. 



The superficial glia-layer (subpia of Waldeyer, gray cortical layer 

 of older authors) exhibits great individual variation. It is thickest at 

 the lips of the sulci and exits of the nerves. Where most developed 

 the fibres have a circular, radial, and longitudinal course, forming a 

 meshwork connecting directly with the glia septa. All vessels and 

 septa from the pia are clothed with such a glia coating. 



The greater number of radial septa are of glia nature, but a con- 

 siderable number of irregular connective septa arise from the pia. 

 Larger masses of connective tissue follow the vessels and these to- 

 gether constitute a considerable element in the framework. 



Ganglion Cells and their Spongioplasmic Skeleton. 2 



The author continues his studies upon the microscopic structure 

 of the invertebrate ganglion cell, founding his studies on Leydig and 

 Nansen. 



As Leydig said there is such a blending of the spongioblastic 

 frame-work of the cell with the connective tissue surrounding that it 

 is impossible to say where one terminates and the other begins. 



Numerous examples are chosen from gasteropod mollusks. Two 

 sorts of spongioplasm fibres, fine and coarse, and a considerable va- 



1 Schaffer, J. Die oberflachliche Gliahiille und das Stiltzgeriist des weis- 

 sen Ruckenmarks-mantels. Anat. Anz., IX, 8. 



2 Rohde, E. Ganglionzelle und Neuroglia. Arch. f. mik. Anat., XLII, 3, 



