Band 125. Nr. 22. XXXV. Jahrgang. I. Bd. Nr. 22. 



Botanisches Centralblatt. 



Referirendes Organ 



der 



Association Internationale des Botanistes 

 für das Gesamtgebiet der Botanik. 



Herausgegeben unter der Leitung 

 des Präsidenten: des Vice- Präsidenten : des Secretärs: 



Dr. D. H. Scott. Ptof. Dr. Wm. Trelease. Dr. J. P. Lotsy. 



und der Redactions-Commissions- Mitglieder: 



Prof. Dr. Wm. Trelease, Dr. G. Bonaventura, A. D. Cotton, 



Prof. Dr. C. Wehmer und Dr. G. H. Ostenfeld. 



von zahlreichen Specialredacteuren in den verschiedenen Ländern. 



Dr. J. P. Lotsy, Chefredacteur. 



•M« rt«? I Abonnement für das halbe Jahr 15 Mark 



durch alle Buchhandlungen und Postanstalten. 



I 



1914. 



AUe für die Redaction bestimmten Sendungen sind zu richten an: 

 Redaction des Botanischen Centralblattes, Haarlem (Holland), Spaarne 17. 



Compton. R, H., An Anatomical Study ofSyncotyly 

 and Schizocotyly. (Ann. Bot. XXVII. p. 793—821. 41 textfig. 

 1913.) 

 The present paper is divided into two parts, dealing respecti- 

 vely with syncotyly and schizocotyly. In the first part the anatomy 

 of normal and syncotylous seedlings of Swaiusona Cadelli, Helian- 

 thus annuus and Prunus dotnestica are described and compared. In 

 Swainsona the lateral union of the cotyledons produces practically 

 no modification in the vascular anatomy, while, in the layer seed- 

 lings of Helianthiis and Prunus, syncotyly leads to elimination and 

 compression of vascular bundles together with reduction in the 

 type of symmetry of the root. After these observations have been 

 dealt with, the whole subject of syncotyly is discussed, special 

 stress being laid on the quaestion of the nature of the so-called 

 syncotj^lous seed-leaf of Ranunculus ficarin which the author is in 

 favour of regarding as a Single cotyledon. As regards syncotyly in 

 general the author shows that: 



1. Syncotyly occurs in a great varietj^ of species, normally or 

 teratologically. 



2. In species with albuminous seeds syncotyly usually gives 

 rise to a symmetrical cotyledon tube, 



3. In species with exalbuminous seeds syncotyly is usually 

 asymmetrical, the cot^iedons uniting along one edge only. 



4. The reason for (2) is probablj^ the homogeneity of the sur- 

 roundings of the embr^^^o before germination, for (3) the asymmetry 

 of its environment which produces accumbency and other irregu- 

 larities. 



Botan. Centralblatt. Band 125. 1914. 36 



