474 Scientific Intelligence. 



The matter is one of those, which, like the continuity of proto- 

 plasm throughout the plant, commands from its coordinating- 

 power general acceptance, and should therefore be most carefully- 

 examined and reexamined to ensure complete accuracy of details. 



Courchet's special results may be briefly stated as follows: — 

 Chromoplasts are always formed at the expense of chloroplasts or 

 leucoplasts and can give rise at their periphery to crystals or 

 crystalloids. The pigment is produced in many ways, and as- 

 sumes very diverse characters. The form of the pigment masses 

 is not related to the color, but depends upon its chemical consti- 

 tution and the matters with which they are combined. Blue, 

 violet and rose tints .are generally due to colored cell-sap, 

 although blue pigments are sometimes in the form of crystals or 

 granules which have no relation to the plastids. The orange tints 

 are chiefly due to crystals, or solid masses, and the same is true of 

 most of the yellow tints. Chromoplasts always have a protein 

 stroma combined with the pigment, which latter may be in sucb 

 fine particles as to give an homogeneous appearance to the whole. 

 The pigment may crystallize out of the granule, and present an 

 appearance as if it is quite independent of it, and it may assume 

 the most diversified shapes. The pigment may, under certain 

 conditions, behave exactly like coloring matters found in other 

 parts of the plant, but whether these matters are produced from 

 the green pigment of the chloroplasts or from derivatives built 

 up in those granules it is, as yet, impossible to determine. It is 

 easy, however, to distinguish two types of coloring matters in 

 the plastids: (l) yellow, always amorphous, much more soluble in 

 alcohol than in chloroform and ether, turning blue with concen- 

 trated sulphuric acid, taking on an intermediate green tinge ; (2) 

 orange, more soluble in ether and chloroform than in alcohol, 

 turning blue with concentrated sulphuric acid, taking on first a 

 violet-red or violet tinge. 



Coloring matters in cell-sap do not as a rule turn blue under 

 the action of concentrated sulphuric acid. g. l. g. 



IY. Miscellaneous Scientific Intelligence. 



1. Note on the, work of the American Eclipse Expedition to 

 Japan, 1887 ; by David P. Todd, Astronomer in charge. — In 

 my preliminary report it was stated that the volunteer observers, 

 working, under instructions prepared by me and printed and 

 distributed through the cooperation of the Japanese government, 

 had been moderately successful. Just how successful, it was not 

 possible to ascertain before leaving Japan. But within a few 

 weeks, I have received through our Department of State, a large 

 MS. volume of about seventy drawings of the corona. These are 

 now in process of discussion on a novel system, and are likely to 

 make a trusty contribution to optical coronagraphy. 



Also, through the same channel, came a valuable series of 

 observations of the simple duration of total eclipse, at points just 



