Morphologie. — Physiologie. 29 



theory, in which the genetic spiral and the parastichies are 

 spirals oJ Archiinedes, and points out that a satisfactory and 

 suggestive construction can be obtained if the genetic spirals 

 are represented bv logaritiimic spirals. 



_____ W. H. Lang. 



Dale, E., On the origin, development and morpho- 

 logical nature of the Aeria! Tubers in Dioscovea 

 satlva Lam. (Annais of Botany. Vol. XV. p. 491.) 



Ol the numerous buds which may be present in the leaf 

 axils of this plant the most anterior are arranged in pairs and 

 develop into peduncles; then comes a median bud, which may 

 give rise to a vegetative branch, and posteriorly are two or 

 three median buds, beneath which the tuber originates. The 

 tiibers, the structure of which is described, are morphologi- 

 cally stems bearing axillary and adventitious buds and ad- 



ventitious roots. 



W. H. Lang. 



Britton, Elizabeth G. and Taylor, Alexandrina, Life history 

 of Schizaea pusilla. (Bulletin of the Torrey Botanical Club. 

 XXVIII. p. 1—19. PI. 1—6. january 1901.) 



The gametophyte is a filamentous protonema, irregularly 

 branched, bearing antheridia and archegonia on the same fila- 

 ment; the former singly or clustered on certain branches, and 

 the latter at or near the base of the filament, often on a 

 cushion formed by its division. A symbiotic fungus occurs in 



the rhizoids. 



Trelease. 



Massart, J., Essai de Classification des reflexes non 

 nerveux. (Extrait des Annales de l'Institut Pasteur. 1^01. 

 p. 1—39.) 



Le titre decrit suffisament Tobjet que l'auteur avait en vue. 

 ]\ analyse les reflexes de la maniere suivante. A. Phases 

 de reflexe. B. Duree et intensite des periodes. 1. Excitation 

 (et Sensation), a. Seuil de duree et seuii d'intensite, b. Comble 

 de duree et d'intensite, c. Rebroussement. 2. Conduction et 

 reaction, a. Temps de latence, b. Temps de riposte, c. Inten- 

 site de la riposte. 3. Temps de memoire. La Nature des 

 Excitants est definiee comme suit: A. Exitants internes. 

 1. Age, 2. Forme: Excitants non definis, a. Influence du 

 sommet, b. Polarite, c. Arcure. B. Excitants externes. 1. Ex- 

 citants mecaniques, a. Gravitation, b. Courant liquide, c. com- 

 pression, d. contact, e. secousse, f. Traction. 2. Excitants 

 physiques: a. Lumiere, b. Obscurite, c. Chaleur, d. Froid, 

 e. Ondes hertziennes, f. Electricite, g. Pression osmotique. 

 3. Excitants chimiques. Exitants non definis. a. Oxygene, 

 b. Alealis et acides, c. Narcotiques, d. Eau. La Nature des 



