Morphologie, Teratologie, Befruchtung, Cytologie. 659 



semblances and differences between Araucaria and some other 

 Coniferales. It differs from Agathis in the length of time (approxi- 

 mately 21 months) taken to mature seeds from the first appearance 

 of the seed cone. 



The very considerable number of free nuclei before cell forma- 

 tion, taken with the very large gametophyte, reminds a character 

 of more primitive gymnosperms. The manner in which the free 

 nuclear stage passes into a gametophyte with walled cells is appa- 

 rently different from that reported for any other plant. 



The author thinks it scarcely credible that the type of ovule 

 which has a specialized pollen Chamber securely hidden away at 

 the base of the scale, and which can be reached by pollen only by 

 raeans of special devices, is a primitive type. Such a structure is 

 too complex for a first Step in the evolution of the ovule and 

 seeds. 



Imbedded archegonia have not been found. They are superfi- 

 cial in origin and become overgrown by the neighbouring cells. 

 Identical conditions have been reported in the podocarps. The 

 necks show a closer resemblance to those reported for Podocarpus , 

 than to those of most other conifers. 



Ventral canal nuclei have not been found, but it seems pro- 

 bable that they will yet be found. 



The gametophyte appears to be neither highly specialized nor 

 exceptionally primitive in its structure. The large size and nume- 

 rous and large archegonia are offset by the late development of 

 walls and their persistent delicacy, by the apparent lack of a ven- 

 tral canal cell, and by the rather specialized necks of the arche- 

 gonia. Probably it presents more resemblances to the gametophyte 

 of the Taxaceae and to those of the Taxodineae than to other 

 conifers. Jongmans. 



Cook, O. F., Jointed leaves of Ainygdalaceae. (Journ. Wash. 

 Acad. Sc. II. p. 218—220. 1912.) 



The leaf-bases of the Ainygdalaceae (plum, peach, apricot) are 

 able to persist because of the Joint that allows the petiole to separate 

 and fall of with the blade at the end of the season. At San Antonio, 

 Texas, where these facts were first noticed, the persistent leaf-base 

 of the peach remains alive for a year or for two but finally dies 

 and withers away. In Maryland peach trees the petiole base lives 

 through the winter and separates when the buds start in the spring, 

 leaving a fresh green leaf-scar. 



The apple and its relatives do not share these specialised leaf 

 characters of the stone fruits. There is no Joint above the attachment 

 of the stipules and basal section of the leaf falls off with the rest. 

 In these cases there could be no question regarding the attachment 

 of the stipules to the petiole. 



Another fact that may indicate greater complexity of leaf 

 structure among the ancestors of the Amygdalaceae is the presence 

 of small oblong or spatulate leafy organs on the Upper part of the 

 petiole, taking the place of nectaries. In some varieties of apricots 

 these small accessory blades are of frequent occurrence. They 

 suggest the possibility that the nectaries of the petioles of Amyg- 

 dalaceae may correspond to the marginal glands of the blade and 

 may represent rudiments of divisions of Compound leaves. If this 

 be true the petiole in this group may correspond to the rachis of 



