108 Physiologie. 



tosynthetic machinery, this part not being developed by illumination 

 so quickly as the green pigment is developed, hence the pigment 

 and other parts of the total machinery lie idle at this early stage 

 awaiting the development of the last factor. F. Cavers. 



Miller, E. C, A physiological study ofthe germination 

 of Helianthus annuus. (Ann. Bot. XXIV. p. 693-726. 1910.) 



The author has made a detailed study of the transformations 

 of the reserve materials of the sunflower during germination. with 

 special reference to the transformation of oils. The oils extracted 

 from the cotyledons show low acid values at all stages; those from 

 the hypocotyl at an early stage and indeed throughout germination 

 show high acid values. The author was unable to determine with 

 certainty whether the oils are translocated as such or as hydrolysed 

 products; but the iodine value of the oils decreases as germination 

 advances, and this the author attributes to the absorption of oxygen. 

 In the later stages of germination the oils diminish rather rapidly, 

 while the carbohydrates increase; this is held to furnish further 

 evidence for the established view that during germination oils are 

 transformed to carbohydrates. F. Cavers. 



Pirotta, R., Hanno le piante organi di senso? (Att. Soc. ital. 

 Progr. Sei., V. p. 65—80. Roma, 1912.) 



Pirotta expose la question des organes de sens dans les plantes, 

 en rapport avec les ^tudes les plus recentes. Comme les animaux, 

 les plantes reagissent aux excitants du monde exterieur: les nom- 

 breux plasmodesmes qui unissent les protoplastes des cellules en 

 constituent le reseau de transmission. Haberlandt et Nemec ont 

 formule la theorie des organes des sens dans les vegetaux: ils ont 

 observe trois types ou groupes d'organes sensoriels, correspondant 

 ä trois categories d'excitations: 1°) organes pour les excitations 

 mecaniques. 2^.) organes pour la perception de la gravitation. 3".) 

 organes pour la perception de la lumiere. 



Pirotta decrit en detail les trois categories d'organes en les 

 appuyant d'exemples; il conclut que, quelque soit le sort de la 

 theorie des organes des sens dans les vegetaux, le merite de Haber- 

 lant et de Nemec est tres grand. 



Ces recherches demontrent une fois de plus l'unit^ des pheno- 

 m^nes fondamentaux de la vie et comblent le fosse profond qu'on 

 croyait exister entre les animaux et les vegetaux. 



F. Cortesi (Rome). 



Schryver, S. B., The photochemical formation of formal- 

 dehyde in green plants. fProc. Roy. Soc. LXXXII, p. 226— 232. 

 1910.) 



The author gives a delicate test for formaldehyde. On the ad- 

 dition of phenyl-hydrazine hydrochloride, potassium ferrocyanide, 

 and hydrochloric acid to Solutions containing formaldehyde, a 

 fuchsin-like colour is developed, by means of which the aldehyde 

 can be estimated when present in small or even extremely minute 

 amount, such as one part in one million. It was found to be present 

 in samples of Chlorophyll prepared from grass on both bright and 



