34 botanical gazette. [February, 



into it from their center organs called haustoria by which 

 they asorb the elaborated juices as roots take moisture from 

 the soil. They differ from true roots, as does the root-acting 

 end of the stem, in the absence of a root-cap. 



An attempt to remove the dodder from a stem to which it 

 is well attached often ends in taking with it at least the cor- 

 tex of the plant on which it grows. Sections either longitu- 

 dinal or vertical through the parasite, in position on its host, 

 median as regards a sucker, will explain this. Each sucker 

 starts, as does a root, in the vascular tissue of the stem, and 

 is a cylinder, sharpened like a blunt pencil where it enters 

 the host and enlarges immediately afterward. Thus is made 

 a sort of neck about which the epidermis of both host and 

 parasite fit very neatly ; the sudden enlargement of the lat- 

 ter, in its new quarters, serving, as does a nut on a bolt, to 

 prevent its easy removal. 



The suckers, in their origin, are domes of meristem tissue 

 before they reach the epidermis. Whatever lack of discern- 

 ment the dodder may show in its selection of a host, once 

 well placed, it lives up to its opportunities. It may, and 

 usually does, in a woodv stem like that of Solidago, send 

 one root into the center, as if for deep anchorage," but spreads 

 out by tar the larger portion of its absorbing tissue in the 

 cambium and sieve-tube regions where elaborated material 

 is most abundant. Its tissue is easilv distinguished from 

 that of the host by its enlarged thin-walled cell 



— — 4u ^ ui u ^uv, ^incii uiaiiciitru, now- 



ver, in a variety of ways inside the host. When growing 

 on hollow stems like grasses, as it was common to find them, 

 tunit U m scarce l v branched, there being little oppor- 



One of the most singular phases of dodder life was a sort 



With at 



of self-grafting or self-parasitism. 



ditticult to distinguish which was host and which guest, as 

 the haustonum extended from the vascular region of one 

 stem to the same of another. In examining the alcoholic 

 speamens, I found this common, and it has often been re- 

 peated on those growing in my own room, usually under 

 such Circumstances as these: If a parasite had occasion to 

 twine about an already thickly covered host, in its anxiety to 

 obtain is share o< elaborated material, it was willing to take 

 a sort of second mortgage upon it, after it had passed into 



