FOUQUIERIA-OPUNTIA, FOUQUIERIA-CARNKGIKA , ETC. 45 



was offered for repeating- the experiments with regenerated slips. Similar 

 preparations with Cereas remained alive entirely through the arid fore- 

 summer when inserted in the stems of Carnegiea. 



FOUQUIERIA-OPUNTIA, FOUQUIERIA-CARNEGIEA, AND FOUQUIERIA- 



ECHINOCACTUS. 



A large number of cuttings of Fouquieria, both fresh and regenerated, 

 were inserted in stems of Opuntia, Carnegiea, and Echinocactus at various 

 times, many with and some without seals. A few of these cuttings were 

 alive after 6 months, their contact yielding some water to them, yet in no 

 case was any activity in the way of leaf-development displayed. Decay 

 ensued in the majority of cases. 



COTYLEDON-OPUNTIA. 



February 4, 1909. — Two regenerated cuttings of Cotyledon macrantha 

 were inserted in joints of Opuntia castillce which remained alive for several 

 weeks by reason of contact with moist tissues, but no growth was made, 

 the leaves withered, and finally the stems died also. The repetition of 

 the test with 0. blakeana gave similar results. 



COTYLEDON-CARNEGIEA. 



On May 17, 1909, two regenerated slips of Cotyledon macrantha were 

 set in cavities on the north side of a trunk of Carnegiea and sealed with 

 plaster, one having been previously arranged. 



June 12, 1909. — All of the preparations were alive, but no growth had 

 been shown by the parasite. 



October 11, 1909. — One of the parasites survived. The stem of the slip 

 appeared plump and turgid and the terminal bud healthy, but no forma- 

 tion of leaves had taken place. 



November 9, 1909. — Dissection of the remaining preparation showed no 

 root formation by the inserted member, all growth having taken place at 

 the expense of balance carried, except such as might have been taken in 

 through non-active tissues. 



COTYLEDON-ECHINOCACTUS. 



On February 4, 1909, two regenerated slips of Cotyledon macrantha which 

 had been fixed in cavities in the body of an Echinocactus in the open, a few- 

 days previously, were alive. One of the slips soon perished, but the other 

 persisted until midsummer, when it was killed by the high temperature. 

 No penetration of the host was effected. 



AGAVE-ECHINOCACTUS. 



In May, 1909, a small Agave was set in a cavity in the body of an Echino- 

 cactus in the laboratory and sealed with plaster. The leaves elongated dur- 

 ing the summer, and when the plaster was removed, early in October, 1909, 

 the central stem was swollen, a secure anchorage had been obtained, and 

 three buds were found in the axils of the old leaf-bases which were removed. 



