368 SUI'HRFiriAl. l'LN<;i. 



The reproductive bodies which Theissen terms " ])ycno- 

 thecia," are formed in the thallus ; they usually develop between 

 the axial strand and the marg-in. Certain cells of the thallus 

 become raised, and the cell walls thickened, forming a circular or 

 elliptical cavity ; as the pycnothecium developes these cells divide 

 in all directions, causing an increasing arching of the membrane, 

 and finally form a compact, opaque, arch, consisting of several 

 layers of short, firm, ix>lygonal cells. The asci and spores 

 dehisce through an irregular opening, caused by the rujKure of 

 certain cells at the apex. 



This structure is obviously distinct from the thyriothecia of 

 the Micvothyriaccce, the only point in common being the hemis- 

 pherical form of the mature 'fruiting bodies. 



The following grouping (vf the families has therefore been 

 suggested ; for these superficial ascomycetes : — 



Perithecia spherical, complete. Perisporialcs. Fruiting bodies 

 hemispherical HcmispJucrialesJ^ 



The Erysiphaceae and Perisjx^riacea^, described at the begin- 

 ning of this paper, constitute the Perisporiales. In the Hemis- 

 phcrriales the following families can be distinguished : — 



I. Microthyriacecc. — Thyrioceia inverse, radiate, thallus 

 thread-like, persistent or evanescent. 



II. Hcmisphccriacece. — Thyriothecia originating from a net- 

 like branching of the hyphse, not radiate, thallus as in Micro- 

 thyriace<T. 



III. Trichopcltacece. — Thallus a radiate membrane, ])erithe- 

 cia formed pycnotically in the thallus. 



Botanical Labokatokies. 



Union Department of Agriculture. 

 Pretoria. 



Vaccine Prophylaxis in Influenza — A reix^n 

 on the value of bacterial vaccine as a ])rophylactic against epidemic 

 influenza, by Dr. McCoy, Director of the Hygienic Laboratory, 

 Washington, Dr. Murray. United States Public Health Service, 

 and Dr. Teeter, Stanford University, San Francisco, is printed 

 in a recent issue of The Journal of the American Medical Asso- 

 ciation. Two groups of person.s — 390 in each group, and all 

 inmates of a State mental hospital, under 41 years of age — were 

 vaccinated early in November with a bacterial preparation con- 

 taining Bacillus influenscc, four types of Pncuniococci, Strepto- 

 coccus hccmolyticus and Staphylococcus pyogenes-aureus. Of 

 the vaccinated group, 119 developed influenza, 2j^ developed ])neu- 

 monia, and 10 cases resulted fatally ; amongst the unvaccinated, 

 103 developed influenza, 17 pneumonia, and 7 died. The reporters 

 conclude that " it appears clear from the evidence afTorded by 

 these observations that no protection was afiforded by the 

 vaccine." 



Theissen, F. : Hemisphceriales, Ann. Myc. 11, [5], 468. 



