Morphologie und Teratologie. — Physiologie. 7 



sporcs indicate that the membranes become massive structures 

 while having no organic connection with the protoplast except 

 at one point of contact. A study of the young living spore up 

 to the time when it becomes opaque seems to favor this Inter- 

 pretation and led Fitting to believe that protoplasm could 

 act Lipon structures not in contact with it. Dr. Lyon believes 

 that there is no real Separation of the forming membranes 

 from the protoplasm except as the result of reagents. A study 

 of the living spore is not conclusive because the developing 

 membranes are not of the same density throughout their 

 thickness. Consequently, when viewed in median optical section 

 there is a striated appearance of the two coats separated from 

 each other and from the protoplast by two fluid regions. This 

 view she regards as more consistent with the development of 

 the first type, which is easily interpreted, and the view is more 

 in accord with the current notion that membranes and cell 

 walls are not developed except when in organic connection 

 with protoplasm. Dr. Lyon finds only two membranes, instead 

 of three or more, as described by Fitting and by Campbell, 

 In the first type the endospore appears reiatively late after the 

 exospore is well differentiated. In the second type the two 

 membranes are differentiated simultaneously, although the exo- 

 spore grows the more rapidly of the two at first. The so-called 

 mesospore is merely a layer of the outside coat torn away in 

 making the preparations. This has led to much confusion in 

 naming and describing the spore membranes. 



In 6". rupesiris only two megaspores usually develop in a 

 sporangium, and these are not shed at all but remain in the 

 cid strobilus until the young sporophytes have roots, stems and 

 leaves. Chartes J. Chamberlain (Chicago). 



MONNiER, Alfred, Les matieres miner ales et la loi 

 d'accroissement des vegetaux. < Universite de Geneve, 

 Institut de Botanique, Prof. Dr. R. Chodat. 7^'"'^ Serie. 

 3tmc fascicule. 33 pages et 9 pl.) — Voirausssi CHODAT 

 et MONNIER, Sur ia courbe de croissance des vege- 

 taux. (Bull. herb. Boissier. Tome V. 1905. p. 615 — bl6.> 



Les experiences de Monnier entreprises ä l'instigation de 

 Mr. Chodat ont porte sur I'avoine et le ble sarrasin cultives 

 dans un sol aussi fertile que possible. Pour eliminer les causes 

 d'erreurs individuelles, les pesees porterent chaque fois sur 

 50 plantes toutes developpees dans le meme terrain, dont on 

 d^terminait a plusieurs reprises, au cours de la p^riode de 

 Vegetation, premierement le poids frais, puis le poids sec ainsi 

 que celui de la matiere organique non azotee, de l'azote, de 

 l'acide phosphorique, de la chaux, de la potasse, et de la 

 totalite des cendres. L'operation portait chaque fois sur 

 10 grammes de substance seche, et donnait par consequent la 

 composition moyenne de la plante consideree comme unite. 



