BEHAVIOR OF SPECIES OP CACTI. 13 



striking between the two sets. Of course, those in the house are a 

 little drawn below, but are more normal after they reach a height of 

 2 to 3 feet, being then above the influence of the solid sides of the 

 greenhouse. 



It is common for the various forms to make fruit to a greater or 

 less degree the third year from cuttings. From seed, the fruit is less 

 abundantly, when at all, produced at this age. This is true of the 

 spineless group and the vast majority of the large spiny species of the 

 Mexican highlands, as well as the common forms of southern Texas, 

 when grown at either San Antonio or Chico. However, only plants 

 of the last of these categories grow at San Antonio without protection. 

 For the past five years, however^ we have had 100 or more tender 

 species of miscellaneous origin at San Antonio under partial protec- 

 tion, simply enough to carry them through the winter without freez- 

 ing. They are planted under a framework over which canvas is 

 stretched whenever the predictions point to subfreezing weather. 

 Kerosene stoves are used to keep the temperature above the freez- 

 ing point. Under this slight protection it is remarkable how few 

 varieties have fruited. Of species from the highland of Mexico 

 which have fruited the third and fourth year from seed at Chico, 

 none whatever have produced fruit the sixth year here. Some 

 species * fruited very sparingly, but not until the fourth year. 



Plants of a spineless species 2 and one of the other large spineless 

 forms, after having been transferred from the field to the house as 

 plants 3 feet high and 2 years or more of age, have produced only three 

 blossoms after five years in the house, although they have grown to a 

 height of 10 or 12 feet. On the other hand, all but one of the peires- 

 kias fruit abundantly under the same conditions. Attention should 

 be called to the fact that at San Antonio the housing means little 

 more than keeping up the temperature, for the house is simply a 

 skeleton frame over which canvas is drawn for a very short period 

 during the norther. It is then removed, the solid board sides, 4 feet 

 high, remaining during the dormant season, and the whole thrown 

 open during the summer from March to November. 



LONGEVITY. 



In the propagation of species of Opuntia it has been customary 

 for the horticulturist and propagator to recommend amputation 

 rather freely. The establishment of a new plant from a cutting of 

 an older one is the recommended and usual practice in propagating 

 the plants, and when once established it is universally recognized that 

 it is only a question of time until a resetting will be required on 



1 Opuntia dilJenii, 0. monacantha, O. schumannii, 0. puberula, and 0. delaetinia. 



2 Opuntia fusieaulis. 



