IO4 



PRACTICAL HISTOLOGY. 



[I. 



ing uncovered. Place a little on a slide, add a drop of water, cover, 

 and examine. 



(a.) Observe the stems, consisting of narrow, clear, oblong cells, 

 joined end to end, and on the summit of each are several 

 rows of small spores. The rootlets or mycelium consist 

 of elongated chains of narrow oblong cells. 



The mycelium is composed of much-branched liyphce. 

 The cells, elongated and narrow, composing these are 

 separated from each other by numerous partition walls 

 (fig. 60, e). The walls consist of cellulose and contain 

 protoplasm with vacuoles. 



(b.) Search for one of the hyphas which bear on 

 their free ends a brush-like group of cells, some of 

 Gonkiiophore wn i cn become constricted to form chains of spherical 

 bearing stylo- dylogonidia (fig. 58). The ripe stylogonidia have a 

 onTh^Hyphre green colour, and they give the mould its green 

 ? i m 6 " * C * J appearan ce. 



15. Yeast (H). Place some German yeast in sugar 

 and water ; keep it for several hours in a warm place. Examine a 

 drop of the fluid. 



(a.) Observe the small oval yeast-cells, each with an envelope, a 



large clear vacuole, and granular proto- 

 plasm. 



(6.) Search for one budding, and 

 notice the small faintly granular bud 

 adhering to and projecting from the 

 mother-cell (figs. 59, 60, /). 



Each yeast plant is a single cell or 

 It is composed of a transparent thin delicate 

 envelope or cell-wall, composed of cellulose. When the cell is 



ruptured the empty cell-envelope may 

 be seen in the field. Within is 

 granular protoplasm, containing, as a 

 rule, a clear space or vacuole. Some 

 W ^f7 '"*$>& cells contain a nucleus. 



^ $*K*&^*& '$ (c.) Stain the preparation with a 



watery solution of magenta. Note 

 that all the cells do not stain equally 

 well. The buds on the side are stained 

 of a deep red, a^nd to a less extent the 



Yeast-Cells; g. Bacilli and Micro- protoplasm of most of the Cells. 



16. Micrococci and Bacteria ( H). 



Set aside a solution of peptone or a watery extract of a piece of flesh 

 for some time, until a scum forms on the surface due to putrefaction. 

 Place a little of the scum on a slide, cover, and examine. 



FIG. 59. Yeast-Cells, a. b and c 

 Budding. 



morphological unit. 



