300 BOTANICAL GAZETTE [OCTOBER 
Compositae. LAGERHEI searched diligently but in vain to find it on 
other genera of plants. Its discovery in North Carolina, therefore, is a 
matter of considerable interest, not only because it naturally occurs on a 
different host, but because of its existence in the north temperate zone as 
well as the temperate section (mountain regions) of the tropics. Its North 
American host, Ambrosia artemisiaejolia, is not very distantly related to the 
South American host S>ilanthes, the former belonging to the section Helian- 
theae-Ambrosiinae, while the latter belongs to the section Heliantheae-Ver- 
besininae.? The question of its distribution becomes an interesting one, as to 
whether it is distributed over the intervening territory of Mexico, Central 
America, Panama, and other tropical countries; or whether it has been by 
chance imported from one country to the other through commerce; or finally 
whether ages ago, when the territory from the southern United States to 
Ecuador may have had a different climate, the parasite might have existed 
throughout this range, but now is serarated by a tropical belt. I hore that 
collectors may be on the lookout for it in other parts of the United States 
and also in the intervening tropical region. I should be very glad to 
receive material in order to obtain further information as to its distribution. 
The form of the plant may be briefly described as follows: When 
mature it may be likenéd to a miniature flask with a long slender tortuous 
neck; while from the base, or from the sides or both, rhizoid-like process€s * 
extend, which branch profusely in a very peculiar and characteristic man- 
ner. In general its form might be likened to that of a giant Entophlyctis, on€ 
of the chytridiaceous endobiotic parasites of the algae. In its development 
the zoospore, at rest on the epidermis, germinates, the germ ag 
enters between the cells and moves on toward a fibrovascular bundle 
Where it branches, the branches making their way between the cells parallel 
with the bundles, so that on the stem the mycelium extends both upw 
and downward. On the leaves the parasite is also confined to the vascular 
bundles. The entire mycelium at certain stages of development is crowde 
with a reddish-yellow oil, which at maturity of the temporary zoosporang! 
or of the resting sporangia, is withdrawn along with the protoplasm aie 
the main body of the plant. The zoosvorangium rests within or i 
fibrovascular bundle and arises by a swelling of the mycelium at the yao 
where the entering germ tube branches. The sporangia vary greatly 
shape, They are oval, subtriangular, elli>tical, etc., and vary from 5° 7 
in diameter (the smaller ones on the leaf) to 200-300 #. The terminal 
mycelium is provided with numerous short haustoria, many of which . 
applied very closely to the spiral ducts. In the resting sporangia itt 
? See HorrMan in ENGLER AND Prantt, Pflanzenfamilien 45: 220 and at 
