NOTICES OF BOOKS AND MEMOIRS. 379 



regulator of respiration, the materials of which are furnished by 

 the protoplasm including the primordial sac and the grains 

 imbedded in it. 



The author has also discovered in the ground substance of all 

 examined chlorophyll-grains, and of all amorphous chlorophyll, a 

 new body very sensitive to light and easily destroyed by it. This 

 he calls hypochlorin or hijpochromijl, and it may be obtained by 

 placing any green tissue in weak hydrochloric acid for from twelve 

 to twenty-four hours. It then appears in the form of very small 

 drops or masses, of semi-fluid consistence, gradually becoming 

 crystalline scales or agglomerations, and finally longer reddish- 

 brown obscurely crystalline scales. In the unprepared tissue it is 

 an oily substance extending throughout the chlorophyll-grains, 

 soluble in alcohol, ether, oil of turpentine, and . benzole, but 

 insoluble in water and saline solutions. " The universality of the 

 appearance of this body in all green chlorophyllaceous plants, its 

 origin in light, its behaviour to oxygen, and its relation to the 

 starchy contents of chloro.phyll-grains, allow scarcely a doubt to 

 arise that it is the true x^rimary product of assimilation of green 

 plants, from which are derived, by oxidation under the influence 

 of light, the starchy and oily contents of chlorophyll-grains." For 

 ordinary illumination chlorophyll is a sufficient protection to hypo- 

 chlorin ; but this is no longer the case under more powerful 

 illumination, nor under ordinary illumination in an atmosphere of 

 oxygen. 



Accumulation and growth of the starchy contents of the chlo- 

 rophyll-grains proceed hand-in hand with a decrease of the hypo- 

 chlorin in it. In darkness hypochlorin is more stable than starch, 

 showing that its conversion into more highly-organised bodies in 

 the cell is favoured by the increased respiration occurring in light. 



S. M. 



Eucalyptogmphia. A Descriptive Atlas of the Eucalypts of 

 Australia and the adjoining Islands. By Baron Ferd. von 

 Mueller, K.C.M.G., &c. Decades 1 & 2. Melbourne, Ferres ; 

 London, Triibner, 1879. 



We have here the first two parts of a work which will be of 

 wide usefulness. Its author has been long accumulating material 

 for it ; he has already published much on the genus in the 

 • Journal of the Linnean Society,' in his ' Fragmenta,' and 

 elsewhere. The complete monograph by Bentham, in the third 

 volume of the 'Flora Australiensis' (186G), brought into a well- 

 ordered system aU that was then known of the botany of the genus. 

 StilL comparatively few of the numerous species have been figured, 

 and as they form the chief timber over the whole Austrahan 

 Continent, and some are becoming widely circulated in other 

 countries, a series of good illustrations is much wanted. 



The plates are of quarto size, lithographs of the same kind as 

 those in the author's ' Victorian Plants,' clear, but somewhat stiff 

 in drawing. Ten species are given in each part, and each also 



