C. A. BARBER. 37 
haustorium as has been described by Fraisse in attacks by 
Osyris alba.’ , 
The effect of the secretions on starch appears to be rather 
slow. In nota few cases starch grains have been found in the layer 
of secretion and disorganized cells of the host after all traces of 
the cell-walls have disappeared (Plate VIII, figs. 4 and 5). This 
seems to suggest that the ferment secreted by the sucker cell is 
chiefly cyto-hydrolytic and, when we consider the abundant 
assimilating foliage of the parasite and its need before all things 
of water and salts, this does not appear strange. A somewhat 
similar state of affairs was observed in Santalum (Part II, para. 
33) where Peirce’s’ observations on Cuscuta were alluded to. 
Brown and Morris* report that in the germination of barley the 
tarch is not acted on until a certain amount of solution has been 
effected and the cells have been isolated. Newcombe* has given 
an extreme case in the ferments of germinating seeds of Lupinus 
and Phenix, the ferments dissolving the cell-walls being hardly 
at all diastatic. It is all the more interesting to note Fraisse’s 
observation quoted above that, opposite to the sucker cells of the 
haustorium of Osy7is, a zone of cells free of starch indicates the 
region of its activity. 
18. It was noted in Santalum that self-attached haustoria, 
that is, such as were fixed on other sandal roots, differed in cer- 
tain respects from those attacking foreign roots. The relations 
between host and parasite in these cases varied. In several 
instances it was difficult to separate the tissues of the two where 
1 Fraisse Sur le Parasitisme de l’ Osyris alba. Comptes Rendus Acad. Sc. Paris, 
30 Jan. 1905. Fraisse states that every root attacked, whether perforated or not. shows a 
region devoid of starch, “ qui délimite le zone d’action du mamelon haustorial.” 
2G. J. Peirce, on the Structure of the Haustoria of Some Phanerogamic Parasites. 
Annals of Botany, VII, 1893. Peirce describes the action of the sucker cells of Cuscuta 
gloumerata upon the mesophyll of balsam leaves. He states that the large thin-walled 
papillate cells dissolve and bore the walls of the cells they are in contact with, making 
perforations little wider than their own diameter. They dissolve the contents rather slowly, 
starchy substances first, protoplasmic later. 
8 J. R. Green, On Vegetable Ferments. Annals of Botany, VII, 1893. 
4 F. C. Newcombe, Cellulose Enzymes Annals of Botany, XIII, 1899. 
