Guilliermond - Atkinson 



— 156 — 



Cytoplasm 



In most fungi, except for the Phycomycetes, the vacuoles appear 

 in the tips of the growing hyphae as very numerous, small, globular 

 elements which sometimes stain uniformly and deeply with the 

 vital dyes and sometimes remain uncolored but contain a deeply 

 stained corpuscle showing Brownian movement (Fig. 100). These 

 vacuoles swell in regions farther away from the tip, then coalesce, 

 until, in the regions still farther away, they form large colorless 

 vacuoles filled with deeply stained corpuscles. These bodies swell 

 after a time, then may dissolve and give the vacuole a diffuse and 

 homogeneous color. This is also true in the yeasts in which there 

 exist in the bud several small, spherical vacuoles, sometimes uni- 

 formly stained with neutral red, sometimes not 

 stained at all, but containing colored corpuscles. 

 These small vacuoles fuse during the growth of 

 the bud until there is present only one large vacu- 

 ole or a few large vacuoles filled with stained cor- 

 puscles showing Brownian movement. (Fig. 101). 

 In some of the lower plants, the vacuoles de- 

 velop quite differently. In many algae, the Con- 

 jugatae for example, they are always in the form 

 of large liquid vacuoles. In other algae they 

 may, on the contrary, appear during the entire 

 cellular development as very small, semi-fluid, 

 usually globular, vacuoles, scattered about in 

 the cytoplasm and never undergoing hydra- 

 ,„SXnJ;;-t.'^vftai tion. These vacuoles, formed of a very concen- 

 staining with neutral tratcd colloldal solution, stain homogeneously and 

 vacuoLf ''n/T*^co^tafn deeply with neutral red, usually without precipita- 

 intenseiy colored gran- ^jqj^_ -pj^jg jg ^j^^ ^ q£ vacuolc generally f ound 



ules {CM) which . ., ^, , ^ ,, , ,t-, i t-. • t • j 



show Brownian move- m thc Phytoflagcllates (Euglcuas, Peridmieae and 

 ^spond"to''b^L''°of Volvocales observed by the Dangeards), in cer- 

 metachromatin ob- tain land forms of the Chlorophyceae (Pleuro- 



coccus, Pleurastrum, Prasiola reported by PUY- 

 maly). The Cyanophyceae also contain similar 

 vacuoles which are found localized in the parietal 

 cytoplasmic layer surrounding the central body, 

 i.e., the region which corresponds to the nucleus (GuiLLlERMOND). 

 The bacteria seem to belong to this category. In them, by vital 

 staining or after fixation, there are observed, especially at the 

 poles of the cell, metachromatic corpuscles which seem to corre- 

 spond to small vacuoles with very concentrated metachromatin 

 (Guilliermond, Mile. Delaporte). Vacuoles of this type are en- 

 countered in the conidia, in the spores and in the zoospores, of 

 fungi and algae (zoospores of Saprolegniaceae and Ulothrix (Fig. 

 103), for example), and in pollen grains (P. Dangeard, Mile. Py).i 

 The data which we have just reviewed, confirm, therefore, the 

 observations of P. A. Dangeard. These data show that vacuoles 



tained with Bouin's 

 fixative stained with 

 haematein. Gl, lipide 

 granules around vacu- 

 oles. 



iMlle. Py has shown that in dehydrating pollen in a vacuum, a solidification of these 

 vacuoles is obtained. The vacuoles become comparable to aleurons grains withm the pollen 

 grains, although the pollen grains do not lose their viability. 



