QUARTERLY CHRONICLE. 209 
the Museum of Cambridge, U.S., which had been furnished 
to the author by Professor Agassiz. 
The paper is one of the most valuable memoirs on the 
subject that has ever appeared. The observations respecting 
the calcareous deposits in the integument, some of which are 
stated to be formed of that form of carbonate of lime termed 
arragonite, will be found highly interesting to microscopists. 
Max Schultze’s Archiv fur Mikr, Anatomie.—Vol. III, Ist and 
2nd Parts.—We have to notice the two parts of our valued 
contemporary issued for the first part of the present year. 
The papers in the first number are the following : 
1. ** Researches on the Physiology of the Phycochromacee 
and Floridee,’ by Dr. Ferdinand Cohn, of Breslau. 
2. ** Researches on Microphotography,” by Dr. Berthold 
Benecke, of Konigsberg. 
3. “ On the Sculpture of the Siliceous Shell in Grammato- 
phora,’ by M. Schiff, of Florence. 
4. “ On the Structure of the Liver of Vertebrate Animals,” 
by Dr. Ewald Hering. 
5. “On the Epithelium of the Macule acustice of Men,’ by 
Dr. Odenius. 
6. “ Note on a Yellow Injection-fluid,” by Prof. Hoyer, of 
Warsaw. 
Dr. Cohn, in his paper, which is one of considerable ex- 
tent, has made use of the spectrum in examining the colour- 
ing matters ; and his researches on that account, as also from 
their relation to the movements of low organisms, and his 
other observations elsewhere noted, will interest our readers. 
Dr. Cohn thus gives his results in extenso at the conclusion 
of his essay : 
(1) The verdigris colouring matter of the Phycochromacez 
—namely, the Phycochrome of Nigeli—is a compound body, 
consisting of a green matter known as chlorophyll, which is 
insoluble in water, but soluble in alcohol and ether, and of a 
blue matter to be called Cohn’s phycocyan, which is soluble 
in water, and insoluble in alcohol and ether. (This latter 
must not be confused with the phykokyan of Kiitzing, which 
is synonymous with the phycochrome of Nageli; neither with 
the phycocyan of Nageli, which corresponds with the blueish- 
green modification of phycochrome.) 
(2) In the living cells both colouring matters are inti- 
mately connected and form a mixed colour, phycochrom. In 
consequence of the changed osmotic relations which take 
place on the death of the cells, the phycocyan is dissolved in 
the water which penetrates by endosmosis, and then appears 
