ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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generally found, in a very sandy soil which is constantly flooded by 
water. Their form, and the fact that the knees as well as the lower 
part of the stem are usually hollow, gives the necessary elasticity to 
resist the strain of high winds on the enormous weight of the crown 
of foliage. When the tree grows in dry upland situations it does not 
produce these knees. 
Spines and Emergences of Euryale.* * * § — Prof. G. Arcangeli describes 
the hairs and spiny protuberances found on the leaves, leaf-stalk, flower- 
stalk, and calyx of Euryale ferox. The latter are of four distinct kinds, 
two of which may be classed as emergences, springing from the 
epiderm or hypoderm, the other two as arrested branches or spines. 
The stellate bodies which are found on the leaves and floral organs 
contain large deposits of calcium oxalate in their cell-walls, and answer 
the double purpose of fulfilling a mechanical function and of eliminating 
excess of calcium oxalate. The author proposes to bestow on them the 
term cladosclereids. 
Intumescences.! — By this term Herr P. Sorauer designates those 
small knot-like excrescences on leaves, usually of a yellow colour, which 
are the result of an elongation of the cells without any considerable 
increase in their number. They are a pathological phenomenon, the 
result of the presence in the tissue of an unusually large quantity of 
water at the same time that transpiration is strongly checked. 
Tuber of Corydalis.J — According to Herr L. Jost, the tuber of 
Corydalis solida differs essentially in structure from that of C. cava , 
which is an abbreviated rhizome. It consists, at the time of flowering, 
of three distinct portions : the uppermost portion has the typical struc- 
ture of a stem, is provided with scale-leaves, and is penetrated by leaf- 
traces ; the lowermost has the structure of a root, and is provided with 
lateral roots ; while the central and largest portion presents, from a 
morphological and anatomical point of view, an intermediate structure, 
and is always formed from the cambium of the parent tuber. This 
description does not apply to the tuber in its earliest condition, which is 
simply a swelling of the hypocotyl, and is renewed annually. A similar 
structure is found in all the species belonging to Irmisch’s section of the 
genus “ Pes gallinaceus,” which includes, besides C. solida , C. fabacea , 
pumila, bracteata , longifolia , angustifolia , nudicaulis , caucasica, laxa , 
densijlora, and kolpakowskiana. As in other species of Corydalis , the 
embryo has only a single well-developed cotyledon. 
Production of Fruit without Fertilization^ — Dr. Fritz Muller 
records several instances of the production of fruit in plants in which 
access of pollen to the pistil was impossible, viz. in Cycas revoluta, and 
in a species of Hedyosmum. In the latter case the seeds were apparently 
well developed, but dissection showed most of them to be empty. 
* Nuov. Giorn. Bot. Ital., xxii. (1890) pp. 266-71. 
f Bot. Ztg., xlviii. (1890) pp. 241-52. 
x T. c., pp. 257-65, 273-82, 289-94 (1 pi.). 
§ Biol. Ceotralbl., x. (1890) pp. 65-6. 
