ENTOMOLOGIST AND BOTANIST. 



349 



p. S.— AiKiusT 29, 1S70. — I have to-day fouud, 

 at Sandwich, Ontario, on tlie Detroit river, tljc 

 Wolffia Colmnltiana, Kars., in full flower. I 

 inclose specimens, but hardly hope they will 

 arrive in perfection. The surface of the pool 

 where I found tlieni, and where I have watched 

 them for more than a year, is covered with the 

 little plants tor more than three-quarters of an 

 inch thick. H. G. 



[For the benefit of some who may be unac- 

 •luaintcd with the i)lants mentioned in the com- 

 munication of Mr. (Jillman, we may state that 

 the species of Lemna are extremely minute 

 plants growing on the surCaco of ponds and still 

 waters, and sometimes called Duckweed. Tlie>- 

 vary in size from one-twclf(h to one-quarter of 

 an inch, consisting of a simple leaf-like body 

 with slender roots emitted from the undei- sur- 

 face. They rarely i)roduce flowers in this 

 country, the usual mode of reproduction being 

 by the development of small, bulb-like bodies 

 from the edge of the leaves ; these bulbs sink to 

 the bottom of the water in the fall, and rise to 

 the surface for development in the spring. The 

 Bowers, when they do appear, are produced from 

 a slit or opening in the edge of the leaf; they 

 are reduced to the simplest state, one or two 

 producing a single stamen, and one or two a 

 single pistil. 



The VVolftia is a plant of similar nature, of 

 microscopic size and simpler structure, each 

 plant producing a single flower of stamen and 

 pistil, formed by a small cup-like depression in 

 the body of the leaf or iilant. — Eu.] 



VEtiETAl'.LE CELLS. 



ItY DU. l-'ELIX SCHAAN, CHICAGO. 



1> A U T III. — CoNli/i Hill from pagi 2.'ili.) 



Oxalate of Lime in < 'uctiis. 



3. Crystals. In the vegetable cells we often 

 find crystals of oxalate of lime; they crystalize 

 in form of (piadratic octahedrons. It is seldom 

 we find this octahedron well developed ; you 

 see a large heap of plates agglomerated irregu- 



larly one to the other. lu Cactus you find them 

 in every slice. Ucranium presents also a large 

 amount of cells containing crystals. (See Fig. 

 137.) 



Schlciden says that oxalate of lime crystals 

 can Lake also the form of needles. I had some 

 doubt whether all necdle-shaiied crystals were 

 oxalate of lime, and, on incjuiring, I went to 

 the following statements. The crystals of oxa- 

 late of lime in the Cactus, I treated with nitric 

 acid. It was not dissolved entirely, but cor- 

 roded oidy on the edges. I added a drop of 

 ammonia, and I saw that the crystal disap- 

 peared rapidly, leaving several gas bubbles. 



1 made a precipitate of oxalate of lime by 

 double decomposition, by pouring into a solu- 

 tion of nitrate of lime, a solution of oxalate of 

 potash, and carefully washing the precipitate, 

 selected on a filtering paper: trying on this 

 oxalate of lime the reactives above mentioned, 

 I found them verified. So it may be stated that 

 these crystals are oxalate of lime. Soine ncedlc- 

 sliai)cd crystals I subnnttcd to a careful stu<ly 

 with the following result: I took for object the 

 rasping of the root of Sarsaparilla {Smilax Sar- 

 sa par ilia). By the addition of a drop of water 

 wc find in the middle of a ring of starch glo- 

 bules a fascicle of needle crystals, and near by 

 you find other needles whose points are broken 

 and scattered in the vicinity. (Fig. 'JI."), a). 

 mt:. -Jir,.] 



In a longitudinal slice of the same root, you 

 may remark between the porous cells and the 

 starch cells a long line of these needle-sha))ed 

 crystals, whose points all look in one direction 

 and follow one another like a procession of ants 

 going to the hillock. (Fig. 215, b). At first I 

 thought — there we have cells with crystals like 

 the Cactus and (ieranium cells, and 1 suspected 

 some porous cells to be the home of these crys- 

 tals. Error! I analyzed the rasping of the root 



