ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
505 
Wings of the Seed of Abietinese.* * * § — Dr. K. von Tubeuf states that 
in all Abietineae, except some species of Pinus , the wing protects the 
young seed wherever the seed is not coalescent with the scale. In 
all the coniferous Gymnosperms the seed is as much protected as it 
would be by an ovary, either by a parenchymatous structure formed of 
conical papillae, or by a dense felt of hairs formed on the margin of the 
scales. 
Arils.f — Herr A. Pfeiffer classifies arils into three groups, according 
to their origin: — (1) From the funicle and its various regions, the hilum, 
the chalaza, and the raphe ( Mucuna , Cytisus, Passifloraceae, &c. ; (2) from 
the exostome ( Euphorbiaceae, Polygalacese, &c.) ; (3) from the tissues 
comprised between the funicle and the exostome ( Myristica , Gelastrus , 
Euonymus, &c.). From an anatomical point of view the aril, whether 
soft or resistant, is almost without exception parenchymatous ; in the 
former case the cells have thin, in the latter case more or less thick 
walls. They usually contain abundance of nutritive matter, of the same 
kind as that contained in the seed. In some cases (Myristicaceae, Con- 
naraceae, &c.) the aril is traversed by small vascular bundles derived 
from those of the placenta. It is probable that arils frequently facilitate 
the dispersion of the seeds, especially when they are winged or fleshy ; 
others contain a transitory store of food-material, which is afterwards 
used up in the ripening of the seed. 
Rhizome and Inflorescence of Paris.J — M. H. Hua describes in 
detail the structure of the rhizome of Paris quadrifolia, and the mode of 
formation of the buds upon it. He asserts the mode of branching to 
be sympodial, similar to that of Polygonatum. The inflorescence may 
be regarded as an indefinite raceme, in which the greater part of the 
flowers abort before attaining complete development, and of which one 
only developes in each year. 
Casting-off of Hairs.§ — Herr R. Keller has investigated the 
structure of the hairs, and the mode in which they are thrown off, in 
a large number of Phanerogams and a few Vascular Cryptogams. The 
throwing-off of the hairs is generally accompanied by more or less 
suberization, and, according to the way in which this is effected, hairs 
may be classified under four types, — (1) Unicellular hairs which break 
off near the epiderm leaving behind a suberized foot ( Juglans , Fagus, 
Ficus, &c.) ; (2) Uniseriate hairs with a well-marked terminal cell, 
which is elongated in the direction either of the base or of the surface, 
or is stellate ; the terminal cell separates from the base (MyrtaceaB, 
Papilionacem, Proteaceas, Pittosporese, &c. ; (3) Uniseriate hairs (or 
branched in one row) in which a varying number of basal cells are 
suberized and the rest thrown off ( Marsilea , Platanus, Nuphar , Nymphsea , 
Ficus, &c.) ; (4) Multiseriate hairs ( Vitis, Quercus, Elseagnus, Begonia, 
Lomaria , Acrostichum, &c.). The fall of hairs is brought about partly 
by internal, partly by external causes, the latter being the more constant ; 
* SB. Bot. Ver, Miinchen, March 14, 1892. See Bot. Centralbl., 1. (1892) p. 73. 
t Engler’s Jahrb. d. Systematik, xiii. (1891) pp. 492-540. See Bonnier’s Rev. 
Gen. de Bot., iv. (1892) p. 191. 
t Journ. de Bot. (Morot) vi. (1892) pp. 161-6. 
§ Nova Acta Acad. Cses. Leop.-Carol. Nat. Cur., lv. (1891) pp. 305-58 (3 pis.). 
