132 University of California Publications in Botany [Vol. 5 



IV. EXPERIMENTAL WORK— 1910 



1. General Habit of Parental Types 



In 1910 the seed of .V. acuminata was sown on March 14 and 

 taken to the propagating house on the same day. The propagating 

 house was thoroughly cleaned and sterilized and the ventilators 

 covered with cheesecloth. The pots were watered from beneath, 

 with the covers on. and these last were replaced in two or three 

 days by glass plates. I have no record of the time of germina- 

 tion or of its amount. The glass plates were not lifted from 

 the pots until the size of the young plants made it necessary. 

 Quite generally toothpicks or pot labels were slipped under one 

 side of the glass so that there might be a slight circulation of 

 air within the pot. After the glasses were removed, much care 

 was taken never to lift or pass one pot over another. When the 

 cotyledons were large enough to be picked up and held between 

 thumb and forefinger, twice the required number of plants was 

 "pricked out" into flats. These wooden boxes or flats — 18 by 

 18 inches — were filled with rich garden soil and the plants so 

 spaced that each flat held 25 seedlings. In "pricking out" a 

 fresh toothpick is used for each seedling to loosen the earth and 

 scrape off soil particles which come up with the fine roots. By 

 carefully spacing the plants in the fiat and watching their 

 development every day or two, there is little danger of any 

 foreign seed germinating and getting established before being- 

 detected. When in the rosette stage and about the tenth of 

 June, the required number of plants was lifted from the flat 

 and placed in the portion of the inclosure set aside for them. 

 The remaining plants in the flat were held for a month in case 

 of accident to those permanently set out. Lack of room neces- 

 sitated the growing of a relatively small number of the X. 

 acuminata plants as well as undue crowding of these. When I 

 saw them first in August there were six plants of variety I, 

 eight of variety II. and fourteen of variety III. In each case 

 the groups of plants were spaced two feet apart, the rows of 

 plants one foot apart and twelve inches left bet^veen the plants 

 in the row. Varieties II and III were within six feet of each 

 other and varietv I was some distance awav. 



