THE FLOWER 283 
Lens-shaped, as in the Lily. 
Spinose, as in the Composita. 
Barrel-shaped, as in Polygala. 
Under the microscope, the immature pollen grain generally 
consists of two membranes, an outer firmer one called the exospore, 
which may be variously marked and which possesses deficiencies 
in the form of “pores” or “clefts,”’ and an inner delicate cellulose 
membrane called the endospore, which surrounds a protoplasmic 
interior in which are imbedded a nucleus, oil droplets and 
frequently starch or protein. 
Po.unta.—These are agglutinated pollen 
masses which are common to the Orchidaceae and 
Asclepiadacea. 
Hay Fever Potiens.—The pollen of many 
plants, notably certain species of Composite, 
Chenopodiaceae, Graminee, Amaranthacee, Fagacee, 
Ulmacea, Salicacee and Juglandacee, has been 
shown to be responsible for “Rose Cold” and 
“Hay Fever.” The chief hay-fever pollens are 
those of the Ragweeds (Ambrosta spp.), Pigweeds 5, 200—Pol- 
(Amaranthus spp.), Docks (Rumex), Wormwoods jinia of a Milkweed 
(Artemisia), Russian Thistle (Salsola), various fapiecinde ¥ svi 
grasses and cereals including timothy, corn, fe = ar vie . 
wheat, oats and Buffalo grass, and a number of ( After Small.) 
trees including the oaks, elms, poplars, black 
walnut, and red cedar. From the investigations of Walker and 
others, it appears that the symptoms of “Rose Cold” and “‘Hay 
Fever” which are seasonable forms of bronchial asthma are 
induced by the sensitivity of individuals to the proteins of certain 
pollens. At the present time pollen extracts, also called pollen 
allergens, pollen antigens and pollen atophans, are manufactured 
from various pollens to be used in the diagnosis, prevention and 
relief of this disease. 
Tue Gynacrum or Pst System—This is the female 
system of organs of flowering plants. It may consist of one or 
more modified leaves called carpels. Each carpel or megasporo- 
phyll is a female organ of reproduction. In the Spruce, Pine, 
etc., it consists of an open leaf or scale which bears but does not 
