1889-J BOTANICAL GAZKTTE. 3$ 



gained three-fourths of an inch in twenty- lour hours— one- 

 third of that length between 8 and 10 a.m. C ireful oh no- 

 vation between the corresponding hours the second day 

 showed the same gain, suggesting, what vperimenl with 

 other seedlings seemed to corroborate, that 8 to 10 ,\. m. rep- 

 resented the maximum period of growth. The plantlet was 

 then, at the height of two inches, touching its host. Contact 

 caused it to coil like a tendril, although it was several times 

 disturbed and shaken from its support, so that at S a. m., 

 Saturday, the 24th, three days after germination, it was fast 

 to its host with two close co'ils about the Stem. Growth in 

 length now ceased for several days, all its energv being ex- 

 pended in producing suckers and thrusting the haustoria into 

 the host. March 26 the suckers were well developed, the 

 root portion was brown and useless, the reservoir above the 

 rhizoid portion exhausted of suppli. i and the plant appar- 

 ently in position for an easv life. During this time the nuta- 

 tion of the tip of the seedling was opposite to the course 01 

 the sun. 



From observation upon this and other plants it was evi- 

 dent that there is a limit to the size of stem they are able to 



encircle, and that the diameter must be small. On that I 



noticed attempting to surround a large geranium stem was 

 unequal to the task, and coiled back upon itself twice upon the 

 side of the trunk. Plants showed very little discrimination in 

 the selection of hosts, attacking everything that offei d sup 

 port — dead and dying stems, as well as fresh ones, and even 

 the rim of the flower-pot- They usually recoiled after one 

 turn about a dead twig, and extended the tip further unless 

 the root had been lifted from the soil. When a suitable host 

 was obtained, the tip nestled down close to it and did not at- 

 tempt further wandering. 



We failed, for a long time, in all our attempts to cultivate 

 the dodder — further than to obtain a few coils about the stem. 

 We never suspected the unsuitable character of the host as 

 out-door dodders do not seem particular. But an enterpris- 

 ing seedling taught us the lesson by seizing a voung gera- 

 nium petiole, just emerging from the bud, and beginning to 

 grow by feet in the same pot where a Eupatorium-entertained 

 companion, of the same age, grew scaly, stubby and by 

 inches, and all others died. After this there was no difficulty 

 in raising dodders. 



The suckers are, outwardly, enlarged fleshy disks, which 

 the parasite forms and presses hard against the host, sending 



