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above another, then they are lower down the stem, hence their elongation is 
much slower ; and, thirdly, some of the sorts, which at first form short 
rhizomatous stems before they take an upright position, require a consider- 
able number of years to perfect the early part of their growth ; but after the 
stem has been formed, and an upward condition taken, the growth is much 
quicker, and the elongation advances rather rapidly, compared with it while 
the stem retained its rhizomatory shape. (Brit. Association, Belfast.) 
The Mosses of North-east of Ireland. — Mr. S. A. Stewart read a paper on 
this subject before the British Association, Belfast. The district he had 
investigated embraced the counties of Down and Antrim, with a small 
portion of county Berry, adjoining Antrim. The species of mosses known 
to occur in this district he estimated at 196, including four species not pre- 
viously recorded as Irish — viz. Fissidens incurvus, Tayloria serrata f Mnium 
subglobosum, and Seligerai pusilla. We have thus in one district rather 
more than one-half of the Irish species of mosses, and more than one-third 
of the entire British moss flora. As might be expected from the geological 
character of the country, the greatest deficiency is in species that prefer a 
limestone habitat. Only 20 per cent, of that portion of the British mosses 
occur here. 
Structural Peculiarities of the Ampelidece. — Professor Lawson' read a paper 
on u Certain Peculiarities in the Indian Ampelidese.” He remarked that 
many of the species were vast climbers, with their branches interlacing in 
the tops of the highest trees. In the stems of all were to be found numerous 
very large ducts, and these ducts were filled with inter-cellular vesicles, in 
which, at a certain time of the year, abundance of starch was developed. 
He , also remarked that in the frond most important differences might be 
found, but that these afforded no means by which to divide the genus. 
With respect to the inflorescence, he said that there was great fixity of 
form. Two species only reached the Eastern coast of Africa, most being 
confined to India, though some few were common throughout the Malayan 
Archipelago. 
Where are the Saprolegniei to be placed? — The “ American Naturalist” 
(June) says that this family, that seems now finally deposited in the Algae, 
has considerable economic interest from the destructive effects produced 
upon fish-eggs in the hatching trays, supposed to be caused by Achlya 
prolifera. The following summary is translated from advance sheets of 
« Contributions to the Morphology and Systematic Relations of the Sapro- 
legniei,” by N. Pringsheim. The results of his investigations on the 
Saprolegniei may be condensed as follows : — 1 . In all the Saprolegniei the 
male organs of generation develop from the well-known antheridia, that 
are formed near or grow toward the oogonia. 2. Those in which antheridia 
or their equivalents are wanting are not, as has been supposed, distinct 
species, with modified organs, but parthenogenetic forms, whose sporangia 
ripen and bud without fertilization. 3. In the Saprolegniei there is but 
one kind of sporangia ; those which develop parthenogenitically and those 
which are fertilized are identical, and show no difference originally. The 
unfertilized zoospores grow sooner and more readily than those which are 
fertilized. 4. Severalpeculiaritiesinthe formation of zoospores, which have 
been considered sufficient specific distinctions, are not important as such, 
