Macrosporium pctrasiticum , Thiim. 5 
spiral (Fig. 4). The portion of the hypha adjoining the spore 
increased in diameter, forming a row of roundish cells for a 
short distance. 
Besides these colourless vegetative hyphae, which grew in the 
fluid, some of the spores produced directly on their surface 
short stout filaments of a brownish colour which grew into the 
air. In cell-cultures, four days after the sowing, secondary 
spores were observed on their ends. They were then still 
small; ovate or oblong in form, and one to three septate ; and 
their wall was smooth and light brown in colour. In some 
way or other their further growth was arrested. The spore- 
bearing hyphae corresponded very closely in their characters 
and proportion to those of the Bermuda specimens already 
described. 
In open cultures with pure water the secondary spores were 
also produced abundantly. On the fifth day they were found 
to have grown to about one-half the size of mother-spores, 
and they continued to grow until they were ripe. They 
showed all the characteristics of the Macrosporium- spores. 
Only in a few cases have I been able to see the spore-bearing 
filaments produced on the hyphae proceeding from the spores 
sown. There were no signs of the formation of perithecia in 
any of the water-cultures. 
On the other hand, the spores which were sown in a 
nutrient fluid presented a widely different result. The main 
hyphae coming directly out of the spores were vigorous and 
grew radially at the rate of about 0.6 mm. daily for the first 
day or two, the rate of growth increasing at quite a rapid 
ratio until about the fifth day of the culture, when it gradually 
decreased. On the third day, the average growth during 
twenty-four hours was 1.8 mm.; on the fifth day, 3.5 mm.; 
and on the sixth day, about 1.5 mm. They gave out lateral 
branches in large number, which, interlacing and anastomosing 
with each other, formed at the end of two days a mycelium 
of about 3 mm. in diameter. The main hyphae were easily 
distinguished by their larger size and straighter course, and 
also by their being copiously filled with fatty globules and 
