PBOGKESS OF MICROSCOPICAL SCIENCE. 89 



There is, however, cause to comjjlain of the treatment of English 

 makers of the microscope, who have no fair position in the list which 

 is given at the end of the volume, and have not a place given to them 

 in the substance of the work. Had such men as Woodward or 

 Richardson been the editors, this would have been very different. 

 However, we have to express our gratitude to the editor for what he 

 has done, and to declare our immense satisfaction with Professor 

 Frey's labours. 



PKOGEESS OF MICKOSCOPICAL SCIENCE. 



The Origin of Leucocytes. — This important subject has been very 

 fully dealt with by M. Feltz, who has i-ecently published a memoir, 

 which completes the views expressed in his earlier paper published in 

 the ' Journal de I'Anatomie.' In this (the first paper) the author con- 

 cludes that the globules of pus which infiltrate the peritoneum do not 

 proceed from the leucocytes of the blood which escape through the 

 walls of the capillaries, nor from the ej)ithelium of that membrane 

 which desquamates at the end of a relatively short period ; and that 

 after their fall leucocytes may still be seen to be produced in the 

 substance of the serous membrane. He now infers from further 

 researches (of which the conclusions are stated in a note addressed 

 to the Academic des Sciences, Feb. 17) that in the peritoneum, as in 

 the cornea, the connective tissue which forms the Aveb of the mem- 

 brane is crossed by a network of canaliculi, the fusiform enlargements 

 of which form what are called the cellular elements of the connective 

 tissue, the connective nuclei, or plasma-cells. These networks consist 

 normally of a simple organic matter (protoplasma of Remak Schulze, 

 &c.), and under irritation, the circulating blood being increased in 

 amount and modified in its plasma, a parallel modification and aug- 

 mentation of the protoplasma ensue, whence the considerable develop- 

 ment of the network of interstitial canaliculi, and of the element 

 styled plasmatic, and its organization into leucocytes. He thinks it 

 not doiibtful that this protoplasm becoming free, as well as by a 

 direct individualization or genesis, as by segmentation and gradual 

 organization of the fusiform swellings, gives rise at once to the form 

 of leucocytes. He hopes soon to be able to give irrefutable proofs of 

 it in the pulmonary alveoli. 



The Liver Ferment. — In Pfliiger's ' Archiv ' there is a paj)er on 

 this subject, which is abstracted in the 'Medical Record,' by Dr. 

 Ferrier. The paper is by Herr Von Wittich. In reference to a 

 recent paper by Tiegel, who found that blood corpuscles under pro- 

 cess of destruction in the liver generated a diastatic ferment, Von 

 Wittich shows that such a ferment can be obtained from blood serum 

 by precipitation with alcohol, and subsequent extraction with glyce- 

 rine, in the absence of blood corpuscles. In addition he finds that 

 the liver-parenchyma itself, when quite freed from blood, yields an 

 active diastatic ferment to glycerine. He allows with Tiegel that it 



