CROSS-FERTILIZATION 



1647 



CROUP 



tied, dull yellow, with the under parts of 

 white. This bird is a winter visitor in America 

 from Pennsylvania to Northern Canada, some- 

 times staying from November until April. It 

 feeds on the seeds of pine cones, fruits, ber- 

 ries and buds of trees, and is said to be very 

 fond of salt. It builds its nest in the upper 

 half of an evergreen, where it lays its three 

 or four tiny, beautiful, pale-greenish, purple or 

 lilac-spotted eggs. A white-winged species of 

 crossbill exists, but is quite rare. 



CROSS -FERTILIZA'TION, the work of 

 water, wind, insects and birds in making plants 

 produce fertile seeds. Those agencies bring 

 the pollen from the stamens of one plant to 

 the pistils of another, thus bringing together 

 the characteristics and habits of two distinct 

 individuals and causing seeds which will either 

 almost exactly reproduce their kind, or in some 

 cases will produce better, stronger, more fruit- 

 ful plants. In self-fertilization the pollen of a 

 plant falls upon its own pistil and produces 

 seeds holding just the same faults or virtues 

 that the parent plant possesses. 



Mother Nature has devised many ways to 

 make sure of this union of traits for the bene- 

 fit of future generations of plants. For in- 

 stance, in some plants, like the geranium, the 

 pistils of one flower are not ready to receive 

 pollen when its own pollen is ripe. Others, 

 like the primrose, have shorter stamens than 

 pistils, so its own pollen cannot reach its 

 stigma. And in some cases, like the willow, 

 one plant bears the male blossoms, another 

 the female. So the winds, the insects and the 

 birds are Nature's pollen carriers. 



And once again Mother Nature has care- 

 fully planned. Those plants which depend on 

 the wind, because their blossoms are brown 

 or greenish, inconspicuous and not attractive 

 to insects, produce large quantities of light, 

 dry pollen, for much of it .will be wasted. 

 And the flowers which hold stores of honey, 

 and advertise with scents and colors to insects 

 and birds, have many ways to make doubly 

 sure their pollen will be reached and carried 

 away or that their pistils will receive pollen. 

 The orchid carries its pollen in little sticky 

 bundles, and the flower is so constructed that 

 in order to reach the store of nectar the bird 

 or insect must reach so far in that a byndle of 

 pollen will glue itself to its head, and when 

 it goes to the next flower the pollen will be 

 brushed on the receptive pistH as the insect 

 pushes in for its honey. The pollen of the 

 milkweed is found in two little bags connected 



by a straplike part; the feet of the bee get 

 tangled, and so it carries away both bags of 

 pollen. The mints are provided with levers 

 which thrust the pistil forward on the pollen- 

 dusted insect. 



In a. general sense, the term crossing, related 

 to cross-fertilization, is also applied in cases 

 of animals and the human race. A limited 

 amount of crossing in similar environments 

 and under similar conditions among species 

 not too closely related produces improved off- 

 spring. See BURBANK, LUTHER; BOTANY. L.B. 



CROTH'ERS, THOMAS WILSON (1850- ), 

 a Canadian barrister and statesman who be- 

 came Dominion Minister of Labor in 1911. 

 After graduating from Victoria College he 

 taught school for four years. He then studied 

 law and after 1880 practiced his profession at 

 Saint Thomas, Ont. Until 1908, though he 

 was always interested in politics, he had taken 

 no active part in public affairs, except in 1879, 

 when he was an unsuccessful candidate for 

 the Ontario legislature. He was elected to the 

 House of Commons at Ottawa in 1908, and 

 three years later, when the Conservative Min- 

 istry headed by Sir Robert Borden was formed, 

 assumed the charge of the Department of 

 Labor. 



CRO'TON AQUEDUCT. See AQUEDUCT. 



CROUP, kroop, a word commonly under- 

 stood to mean a disease of babyhood or child- 

 hood, characterized by hoarse cough and peri- 

 ods of difficulty in getting the breath. There 

 are two forms of the disease spasmodic, or 

 false, croup, and membranous croup. The lat- 

 ter is sometimes confused with diphtheria 

 (which see), but a competent physician can 

 correctly diagnose the ailment without diffi- 

 culty. False croup often attacks feeble or ill- 

 fed children who have suffered exposure to 

 cold and wet or are subject to digestive dis- 

 turbances. The attacks come on suddenly, and 

 the child awakens coughing hoarsely and 

 breathing heavily or gasping. The face be- 

 comes red or purplish, and the patient seems 

 on the verge of suffocation. Paroxysms may 

 last from half an hour to five or six hours, 

 and may occur on several nights in succession. 

 A tea-kettle of hot water placed under a sheet 

 thrown over the child's bed permits inhalation 

 of warm, moist air, a remedy generally advised 

 by physicians. The child should also be given 

 frequent drinks of warm milk, and vomiting 

 should be induced by doses of syrup of ipecac, 

 a half-teaspoonful being given every fifteen 

 minutes as long as is necessary. 



