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HARDWICKE'S SCIENCE-GOSSIP. 



somewhat rectangular cells over the greater part of 

 the leaf surface without getting very near each other. 

 But at the midrib and margin, where the cells are 

 long and narrow, the currents are very close to each 

 other, and the little particles seem to be almost 

 rubbing shoulders as they pass on and on, with a 

 clockwork regularity that is both interesting and 

 amusing to observe. To prevent disappointment, 

 when a leaf is to be exhibited, it is best to have it 

 cut off and placed in a drop of water on a slide a few 

 hours previously, as the shock given to the circula- 

 tion by cutting off the leaf, frequently interrupts it 

 for a considerable time. It will be seen that the 



enclosed in a tubular bifid spathe, they float on the 

 surface of the water. They are rather variable, and 

 botanists have different opinions concerning them. 

 Wood says* they are polygamous ; Babington saysf 

 they are dioecious ;~and Hooker saysj they are sub- 

 dicecious. The male flowers are rarely seen, and 

 according to Babington and Hooker, unknown in 

 England. But having examined the plant carefully 

 in various places during the last two seasons, in the 

 hope of finding either male or perfect flowers, I have 

 at length been rewarded by finding the former 

 growing sparingly in a pond on the Braid Hills, near 

 Edinburgh on the 2nd of August last, specimens of 

 which I inclose. This is probably 

 the first record of their occurrence 

 in Britain, and curiously enough 

 exactly thirty-eight years after the 

 first discovery of the plant by Dr. 

 Johnstone. As they are seldom 

 seen the following diagnosis may be 

 useful. Male flowers : Spathe lobes 

 broad and keel-shaped. Flower-bud 

 roundish oval. Sepals boatshaped, 

 reddish-green, ultimately refiexed. 



Fig. 139. — Water Thyme {Anachai is aLinastnim), male flowers (natural size 



circulation does not take the same direction in every 

 cell. 



The anacharis belongs to the Natural Order 

 Hydrocharidacese, and in addition to the botanical 

 name already given, the following synonyms are in 

 use among botanists : — ■ 



Anacharis canadensis (Planch.) ; A. nuttallii 

 (l'lanch.) ; Elodia canadensis (Mich.) ; and Udora 

 canadensis (Nutt.). It is a dark green, much branched 

 perennial, growing under water. The leaves are 

 numerous, cauline, varying from roundly ovate to 

 oval oblong, minutely serrulate and generally in 

 whorls of three. The flowers are small and sessile, 

 but as they are provided with a thread-like tube from 

 one to ten inches long, the basal portion of which is 



1.; >. — Diagram of flower. 



Petals transparent, narrow from 

 a broader base, refiexed between 

 the sepals. Stamens nine in two 

 rows. Anthers oval, leaflike, in- 

 trorse, nearly sessile, six outer at 

 length sp reading, three inner erect, 

 and generally surrounding a 

 curiously mammillated and very 

 variable pistil (fig. 142) which is 

 sometimes absent. The pollen is 

 abundant, and the pollen grains in 

 clusters of four. 

 Unlike the rather firm textured and comparatively 

 straight corolla-tube of the female flowers, that of 

 the male flowers is very brittle — so much so that it 

 takes very careful manipulation to gather a specimen 

 without detaching the flower; and as it lengthens, 

 the basal portion becomes attenuated and hairlike and 

 sometimes breaks away of its own accord ; but whether 

 attached or detached, the tube is almost always 

 crumpled and twisted like a cotton thread in the 

 water. Though it does not grow either so long or so 

 fast as that of the female flowers of Vallisneria, the 



" Flora of the United States and Canada," p. 679. 1S74. 

 " Manual of British Botany," seventh edition p. 331. 1874. 

 " Student's Flora," second edition, p. 371. 1878. 



