222 BOOKS AND CURRENT LITERATURE 



is also chemically produced in the formation of the complex proteins 

 from peptones, polypeptides, amino-acids, etc. 



Babcock's studies relate largely to the processes of germination in 

 seeds and of ripening in fruits but he records a number of extremely 

 interesting observations on the water relations of such forms as the 

 clothes moth {Tinea pellionella, Linn.), the bee moth, the pea weevil, 

 etc. Larvae of the clothes moth containing from 57 to 59 per cent of 

 moisture developed upon air-dry food material containing from 3.66 

 to 9.08 per cent of water, these organisms receiving no liquid water 

 at any time. The bee moth (Galleria mellonella, Linn.) thrives with 

 even less moisture in the food. Larvae containing about the same 

 percentage of water as those of the clothes moth just mentioned, devel- 

 oped upon comb containing but 1.85 per cent of moisture. The con- 

 clusion is reached that most of the water contained in these organisms 

 must have arisen from the decomposition of the food material; it must 

 be considered as metabolic water. 



The studies which Babcock has carried out on seed germination, 

 especially with maize, lead him to the generalization that low percentage 

 of germination in maize is often due to lack of soluble carbohydrate in 

 the seed. This, in turn, is regarded as due to lack of diastase, which 

 is supposed to be produced only with normal respiration. Hence low 

 viability is traced to lack of normal respiration, due to inadequate supply 

 of oxygen to the stored seed. This idea is supported by such observa- 

 tion as the following: Maize of low germinating power may be made 

 to germinate quite normally if soaked in a diastase solution, as has already 

 been noted by Waugh. Babcock repeated these tests and discovered 

 further that a 3 per cent solution of glucose has the same beneficial 

 effect as does the diastase. Furthermore, maize seed of low viability, 

 if soaked in a 1.5 — or 3 — per cent solution of hydrogen peroxide, is 

 greatly improved, this being apparently due to the acceleration of the 

 processes of oxidation by the oxidizing agent. Incidentally, the hydro- 

 gen peroxide prevents the growth of moulds and the use of a 1.5 per 

 cent solution of this substance is to be recommended in starting ger- 

 mination. Seeds like maize, which do not normally germinate under 

 water, may be made to do so under a weak solution of the peroxide. 



Many interesting and significant observations on the hydrophysi- 

 ology of plants are brought forward in this publication, but these cannot 

 be taken up here. The paper should, on the whole, be considered as 

 a landmark, and should stimulate research along a large number of 

 different lines. — B. E. L. 



