45 



young haustorium, disappear when it attains several years' growth, so that 

 the contact surface of the haustorium becomes simpler and much reduced. 



The question how long can the haustorium of perennial parasites live 

 seems to me to be of special interest, but we know little of it. Scott dis- 

 covered that, in Santalum album, old ha nstoria become functionless and the 

 nutritive connection is then renewed by the young ones ; but he did not show 

 how long could these older ones survive. Heinricher 2} has shown that the 

 haustorium of Lathraea can be active during 2-4 years. If the age of a 

 haustorium can be calculated from the number of annual rings of the host- 

 root which overlie the sucking process, it is safely to be concluded that the 

 same organ of Buchlega can maintain its activity during fifteen years; 

 besides I think that it may be still older. 



The influence of the haustorium upon the host has hitherto been very 

 imperfectly studied in Santalaceas. It has been established by Scott 3) that 

 host- roots attacked by the haustorium of Santalum album undergo no 

 structural change ; with Buchleya, however, a striking change of the host- 

 root attracts our attention. Where the host-root is in close contact with 

 the haustorium, the activity of cambium seems to be much increased, 

 for the cross-section of that part shows the widest wood and cortex. This 

 change would have some important meaning respecting the nutritive relation 

 between the host and the parasite. This point, I hope, will be discussed 

 at fuller length in a future paper. 



The culture of parasitic Santalacese has long been unsuccessful until 

 recently Heinricher 4) obtained many seedlings of Thesium and Osyris 

 in 1899. I have found no difficulties in culturing Buckley a. I have first 

 collected many seeds in the autumn of 1898 and sowed them in the December 

 of the same year in pots with seeds of other plants, which might have 

 served as the host for young Buchleya ; and for control experiment some 

 seeds of Buchleya were sowed in pots without any seed of other plants. 

 No seed germinated in the next year, but first in May 1900 numerous 

 seedlings started forth in every pot and attained to the height of 5-6 cm. 

 at the end of the autumn. I have also obtained at the same time many 



1) Scott, Ueber die einige indische Lorantlms-Arten und ueber den Parasitismus von 

 Santalum album. Bot. Ztg. Bd. XXXII, 1874, p. 149. 



2)Heinricher, Anatomisher Bau und Leistung d. Saugorgane d. Sclmppenwurz-Arten. 

 Cohn's Beitr. Bd. VII, 1895, p. 372. 



3) Scott, loc. cit., p. 149. 



4)Heinricher, Zur Entwickelungsgeschichte einiger griiner Halbsclmiarotzer. (IV- 

 Uiuf. MUheU.) Ber. d. deutsch bot. Gesellsch. Bd. XVIII, 1900, p. (244). 



