Many kinds of plants do not perfect their seed in the open ground, and to accommodate these 
half-a-dozen or more houses are erected. We give a sketch of some of these houses, and also of 
one devoted to the finer kinds of Petunias, known to florists as Petunia grandiflora. This 
variety has very large flowers, often four or five inches in diameter, but produce no seed if planted 
in the open ground, and indeed bear none in the house unless supplied with plenty of air and 
sheltered from the rains and dews ; and even then every flower must be artificially fertilized. 
To meet these requirements a roof, partly of glass, is erected on posts, and entirely open at the 
FERTII.IZING SINGLE PETUNIAS WITH POLLEN FROM DOUBLE FLOWERS. 
sides and ends. The plants are grown in pots, and every morning each opening flower is fer- 
tilized by collecting the pollen on a camel's-hair pencil and distributing it among the pistils. 
This plan is generally, though not always, successful. 
The Double Petunia bears no seed, the natural organs of the flower being destroyed in 
doubling. Seeds that produce double flowers are obtained in this interesting way : A house is 
filled with fine single-flowering plants, in pots, while another house near by is filled with plants 
bearing double flowers. The double flower, while it has no pistils, and but very imperfect 
stamens, does occasionally produce a little pollen. The operator picks a basket of double flowers 
and takes them to the house containing Single Petunias. He then tears the double flowers in 
pieces, searching carefully for pollen, and collecting it with a camel's-hair brush. Every grain is 
DSI 
