282 



c. icon.), non Fischer, Filtrust &. Blaererust (R 02 ^°^ c. icon., Lind &. 

 Ravn 10«), Lit: R 90 a 6. 06 r. 



Heter-eu-cronartium, st. I is perennial in the bark of Pinus, st. II 

 &. Ill on the under side of the leaves of numerous species of Ribes. 

 Klebahn has proved the right correspondence of the two forms (Kleb. 

 88, recorded by Rostrup 90 a ^**). Rostrup has confirmed the observa- 

 tions (R 95 a^"'); he sowed peridermium spores May 9. 1893 and got 

 St. II on Ribes gracile, multiflorum and divaricatum May 23. 



The strange fact that the two host-plants on which it is generally 

 found in Europe, Pinus strobus and Ribes aureum, have been impor- 

 ted from America without the fungus having been known there until 

 in 1906 (F. K. R. 11) it was brought over from Europe, has induced 

 many mycologists to occupy themselves with the peregrinations of 

 this fungus. (A copious list of literature concerning this subject has 

 been collected by Stewart (06), see also Dietel (04)). 



Thus it has been proved that the fungus has emigrated from Siberia 

 where it is found on Pinus cembra without doing considerable injury. 

 It was found by Dietrich in the Russo-Baltic Provinces in 1856 &. by 

 Kornicke in the East of Prussia 1865 (Kcke 77 '*), but was unknown 

 in the rest of Germany till Magnus &. others found it in Stralsund &. 

 Kiel in 1872 (Magnus 74). Already on the 20. of May 1861 it was 

 found on Pinus strobus near Helsingfors (Liro 08 ''''°) &. near Fager- 

 vik in Finland in 1870. In Denmark Cronartium on currant leaves 

 was first noticed about 1865 (R 02 a ^o') 8. 1872 (0rsted 67 c "2); 

 Peridermium strobi was first collected in a nursery at Hersholm in 

 1877 (P. E. Miiller), but according to trustworthy reports it was seen 

 both in Jutland &. in Seeland even before the year 1870. Rostrup 

 was mistaken at first in considering it to belong to Coleosporium 

 senecionis (R 83 d ™', 89 a tab. IV); since 1870 it has spread very 

 widely and is doing great injury both to Pinus and Ribes; the culti- 

 vation of Pinus strobus has in several places been quite abandoned on 

 account of the attacks of this fungus (R 89 a 6.. 93 a ^°^). It is so com- 

 mon that it would take too much time to state all its localities; in the 

 forests of North Seeland, at Tallese and in the forest of Dronninglund 

 Rostrup has noticed hundreds of trees killed by this fungus (90 a ^'^). 



The big sori of Peridermium strobi are often attacked by Tuber- 

 culina maxima (R 02 a ^^°) and are generally devoured by Arvicola 

 glareola (see Boas 96'"). 



St. II 6^ III seem to be able to attack all species of Ribes, although to 

 a very different extent; Ribes nigrum and aureum are most exposed 

 to its attack; on Ribes grossularia it is seldom found; but chiefly on 

 the high-stemmed species, grafted in Ribes aureum (Kleb. 92''^); both 

 Rostrup and I have, however, also found it on red gooseberries. 



