133 BOTANICAL GAZETTE. 



and published by no less an association dian the Federation of Hort- 

 icultural Societies of Belgium. It is entitled "Une Excursion Botani- 

 que au Colorado et dans le Far West" and is translated by Dr. Henri 

 Fonsny, of Verviers. Prof. Jones is collecting largely in the west and 

 enough of his specimens have reached Europe to make him known 

 there, and the desire to know more of the country that produces such 

 plants has led to the writing of th s paper. 



The Iowa Academy of Sciences has published a pamphlet of 

 some 30 pages containing its procedings from August 1875, theda'eof 

 organization, to Julv 1880. The number of Fellows cannot exceed 

 30, and only such persons as have done good scientific work are eli- 

 gible, the assent of three-fourths of the members being necessary 

 to a choice. From the li'^t of Fellows given we nnte b.ut t-^o to whom 

 some branch of botany is credited as a specialty, namely, Prof C. 

 E. Bessey and Dr C. M Hobby The latter gentleman publishes a 

 list of the '"Fresh Water Algie f und in Iowa" Twenty-seven genera 

 are represented by seventy tAO species, Spirogxra containing eighteen. 



The S'J'EM of Pumpkin for Illustrating Plan r Histology. — 

 The stem of the common pumpkin [Ciiciirbi/a Pcpo) is admirably 

 adapted for use in the laboratory to illustrate many kinds of cell-struct- 

 ures, and the larger part of the tissues of the higher plants. It is of a 

 convenient size to be h°ld for sectioning, and after remaining in a 

 sufficient quantity of strong alcohol fir awhile becomes very solid, so 

 that exceedingly thin sections are easily obtained. The cells are 

 comparatively large and a power if 250 to 500 diameters will demon 

 strate almost every detail. 



A cross-section of the stem shows ■". iih uit magnification '^wq 

 small fibro vascular bundles lying beneath the five angles ot the stem, 

 •with the same number of much larger bundles situated between them, 

 but deeper These are imbedded in the fundamental tissue, and the 

 whole surrounded by a cortical rind. The center of the stem is 

 hollow, due to rupture of the fundamental tissue from expansion by 

 growth. Other features of the stem can be made out without a 

 microscope, but it is best to revert to them after their full significance 

 is understood. 



An enumeration of the kinds of cells and tissues to be met with 

 will answer the purpose of this notice, as no extended description is 

 intended. The cortical rind is composed of epidermis and hypoderma. 

 Three forms of cells belong to the epidermal system - simple epider- 

 mis cells, hairs, and guard cells of the stomata, the latter best studied 

 in cross sections of the stem. The fundamental system comprises the 

 large-celled, thin walled parenchyma in which the fibro-vascular 

 bundles lie, and the hypodermal tissues. The parenchyma is colorless 

 and varies little except in size of the ceils. The hypoderma consists of 

 two layers, encircling the stem, partly performing the office of impart- 

 ing strength, and partly containing assimilative protoplasm. The 

 innermost of these is of^ uniform thickness and made up of slender 

 wood cells. Thin transverse septa are occasionally met with, which 



