Morphologie etc. — Varietäten etc. 613 



ched to each other at the apex, and the capsule opens by four 

 longitudinal slits. The beak is best developed in P. radiciilosa,yfh\c\\ 

 has a much more elongated capsule than the other species. In its 

 much shorter and relativ ely broader capsule, P. Zollingeri is more 

 like Mörkia or Calyculana. P. Zollingeri is also like the latter in the 

 tuberculate spores. In P. radiculosa and P. Levieri the spores are 

 reticulately marked. 



To judge from the foregoing study, P. Zollingeri is in some 

 respects more like Mörkia than it is like the other species of Palla- 

 vicinia that were examined. Whether these differences in thallus 

 and sporophyte, combined with the very different habit, are suffi- 

 cient to Warrant the retention of the generic name Mittenia for the 

 dendroid species of Pallavicinia, may be questioned; but on the 

 whole the authors are inclined to think this is justified and the 

 members of the section Eupallaincinia might properly be transfer- 

 red to Blyttia. 



The authors add some remarks on the supposed differences be- 

 tween the Aneuraceae and Blyttiaceae. The production of the repro- 

 ductive Organs upon special branches which appears to be the only 

 constant difference between the Aneuraceae and Blyttiaceae, seems 

 hardl}^ of sufficient importance to Warrant the establishment of two 

 families, especially as, except for the small size of the fertile 

 branches, they do not differ essentially from the ordinary shoots 

 upon which the reproductive organs occur in the Blyttiaceae. 



While it is still too soon to propose a definitive Classification of 

 the thallose Jungennanniales , it ma\^ be said that so far as the two 

 families Aneuraceae and Blyttiaceae are concerned, the differences 

 between them are not of sufficient importance to Warrant the esta- 

 blishment of two families. Jongmans. 



Doyle, J., Some researches in experimental morphology. 

 1) On the change of the petiole into a stem by means 

 of grafting. (Scient. Proc. Roy. Dublin Soc. XIV. N. S. N» 33. 

 p. 405-444. 7 pl. 3 text figs. 1915.) 



The author discusses the literature bearing on the question 

 whether a petiole can be induced to function as a stem. His own 

 experimental work on this point was begun under the direction of 

 Professor Winkler of Hamburg. He used Pelargonium zonale 

 V. ineteor, Solanum (2 sp.), Sanchesia nobilis and Phytolacca dioica, 

 the first named being examined in greatest detail. The lamina of a 

 large well developed leaf was removed and a small apical bud was 

 grafted on the petiole. Such buds grew into vigorous shoots, and 

 the petioles sustaining them assumed the functions of stems and 

 developed certain stem characters, — viz., long life duration, inde- 

 finitely active cambium, interfascicular cambium linking up bund- 

 les, periderm development and considerable secondary growth. The 

 author considers that the causes of the secondary thickering are to 

 be sought in the removal of correlational influences, to the in- 

 creased mechanical strain, and he also suggests, that some influenae, 

 connected with transpiration, is exerted as a result of foliar deve- 

 lopment. Agnes Arber (Cambridge). 



Atkins, W. R. G. and G. O. Sherrard. The pigments of 

 fruits in relationto somegenetic experiments on Cap- 



