16 SMITH: THE HISTOLOGY OF CERTAIN ORCHIDS 
Bourquelot, E., & Bridel, M. Application de la methode bio- 
chimique a |’étude de plusieurs espéces d’orchidées indigénes. 
Decouverte d’un glucoside nouveau, la “‘loroglossine.”’ 
Compt. Rend. Acad. Paris 68: 701-703. 1919. 
MacDougal, D. T. Hydration and growth. Carnegie Inst. 
Washington Publ. 297. 20. 
Czapek, F. Biochemie der Pflanzen. Ed. 2. Jena. Ig2I. 
Explanation of plate 1 
The figures were drawn with the aid of a camera lucida. With the ex- 
ception of Fic. 4 all were drawn from paraffin sections of a young bud of 
Aspasia sp., which was fixed in Flemming s medium solution and stained with 
Flemming s triple stain. Fic. 4 was drawn from a free-hand section of fresh 
material stained with ruthenium red. Magnification of all except FiG. 4, 
1280. 
Fic. 1. Hypertrophied cell with dense cytoplasm in which there is a 
suggestion of a vacuole. This cell, which will produce crystals and mucilage, 
is surrounded by smaller vegetative cells. The nuclei of two such cells are 
shown. 
Fic. 2. Cell with enlarged crystals in a vacuole. 
Fic. 3. Cross section of young mucilage cell showing nucleus with bundle 
of crystals in the center 
Fic. 4. Cell from a i ecuda section of a mature flower stained with 
ruthenium red. The crystals are probably displaced by cutting. The mid- 
dle lamella and thickness of the cell wall are clearly brought out with the ru- 
thenium = The cytoplasm does not yet show the homoger eous appearance 
of mu iy 
we Portion of a cell showing the sheath-like envelope around the 
een sr crystals and its connection with primordial utricle of the cell. 
1G. 6. Portion of a mature mucilage cellshowinga thin layer of cyto- 
plasm between the mucilage and cell wall. In it an elongated deeply staining 
nucleus with nucleole is imbedded. The mucilage is stained a pale 
yellow 
the sheath around the crystals a bright red, 
