1895. ] Anatomical and Physiological Researches. 459 
into maltose. The validity of the observations upon which is 
based Niigeli’s hypothesis as to the growth and structure of 
starch grains isdenied in toto. The grains have their origin 
and growth entirely within chromatophores where they are 
held as long as the cell is living. Growth consists of the 
Superposition of new layers of material on those previously 
formed. The layers or coats are due to the periodic activity 
of the chromatophore. The contour of the grains is due en- 
tirely to the pressure exerted on the chromatophore by the cy- 
toplasm, and the size depends upon the biologic relations of the 
plant. Thus in rapidly germinating seeds or in other struct- 
ures where rapid solution of reserve material is desirable, the 
grains are small, and easily fissured. The granula of the 
chloroplasts are regarded as the organs of synthesis of the 
carbohydrates, and the stroma as the organ of formation of 
Starch material and diastase. In the consideration of the 
morphology of the chromatophore the author is led to con- 
clusions in harmony with Berthold’s theory of the emulsion 
structure of protoplasm. Ina series of monographs which 
form an appendix to the chief thesis, he describes the results 
of his researches on the seasonal periodicity and other bi- 
ologic relations of the starch grains of Dieffenbachia seguina, 
Pellionia daveauana, Hyacinthus orientalis, Cyrtodeira 
Cupreata, Adoxa moschatellina, and Hordeum distichum. 
€ book contains all of the author’s work upon starch, much 
of which has been previously published. It is well illustrated 
and logically arranged. The great number of macro- and 
micro-chemical reactions given makes the work invaluable in 
the laboratory. With this work at hand the archaic: views as 
to the composition, structure, and growth of starch grains 
which find place in the best botanical as well as chemical text 
books will no longer be excusable.—D. T. Mac DouGat. 
Arctic and Alpine plants.! 
The present paper by Bonnier points out the difference in 
Structural development of some arctic plants as compared 
with the same species collected in the Alps and Pyrenees. 
The arctic plants were collected by Charles Rabot, who 
visited Jan Mayen and Spitzbergen in the summer of 1892. 
€ must note, however, that since these plants were col- 
en pe 
*Gaston Bonnier: Les plantes arctiques comparées aux mémes espéces des 
Alpes et des Pyrénées, Revue gén. de Botanique 6: 505-527. p/. ¢. 1894. 
