92 
CHARLES THOM AND MARGARET B. CHURCH 
by Grijns.i^ The validity of both of these determinations is disputed 
by Vuillemin^"^ who probably correctly regards the perithecia found 
by Behrens as belonging to the A. glaucus series and makes those 
described by Grijns the basis of A. pseudo-nidulans Vuillemin. On 
the other hand, the descriptions of perithecia for A. fumigatoides by 
Bainier and Sartory^^ and for A. fischeri by Wehmer^^ are scarcely 
questionable. Both of these forms reproduce the conidial form of 
A. fumigatus within the limits of variation reported for this form 
Fig. 3. A. nidulans (American soil strain no. 131). a, diagrammatic section 
of vesicle with two sterigmata; b, c, primary and secondary sterigmata, X 1,500; 
d, a group of conidia, X 1,500; e, /, g, h, j, diagrams of stalks and heads; k, peri- 
thecium surrounded by sterile hyphae and Hiille-cells (L); I, Hiille-cell enlarged 
showing the thick walls and the granular cell contents; m, a group of ascospores. 
as it is found causing aspergillosis of birds. We have recently studied 
a form obtained from two separate sources in which the conidial areas 
were much reduced when cultivated at 20°-25° C. but developed 
characteristic areas of the A. fumigatus type at 37° C. Perithecia in 
both strains begin to appear abundantly within the first few days 
on Czapek's solution agar but not at all in plain agar (beef-extract- 
1^ Grijns, G. Die Ascusform des Aspergillus fumigatus. Centralbl. Bakt. II. 
11:330-332. 1903. 
1^ Vuillemin, P. Archiv de Parasitologic 8: 540. 1904. 
1^ Bainier, G., et Sartory, A. Bull. Soc. Myc. France 25: 112, pi, 5. 1909. 
i^Wehmer, C. Centralbl. Bakt. II. 18: 390-393, figs. 5. 1907. 
