128 AMERICAN CARNATION CULTURE. 



75 per cent of relative humidity, 50 per cent of sunshine, 45 de- 

 grees of surface and 50 degrees of aerial temperatures. 



The greenhouse treatment of carnations equalizes the ex- 

 tremes of the year's temperature but does not materially increase 

 the number of annual heat units. There is always much moist- 

 ure rapidly passing into vapor in housed carnations and absorbing 

 an immense volume of latent caloric, thus keeping the surface 

 temperature surprisingly low. Moisture and heat are inverse con- 

 ditions. The thermometer and hygrometer teeters with the tem- 

 perature: when one goes up the other goes down. 



The primative La Puritie type of carnations by selection, has 

 been surely drifting into a different species, requiring more heat, 

 which supports the assumption that greenhouse methods for car- 

 nations has raised their annual mean temperature above that of 

 the natural isotherm. Mrs. Lawson, one of the highest types of 

 the new evolved species, was complained of by a grower to its 

 originator, Mr. Fisher, for bursting its calyxes, and he suggested 

 55 degrees night heat as the remedy. This is in full harmony 

 with the author's contention of an evolution of a new species of 

 carnation growing out of adaptation by selection and requiring an 

 artificial or natural isotherm of 55 or 60 degrees of annual he.at to 

 meet the requirements of its nature. 



The 50 degree isotherm leaves all California to the south of 

 its belt. California's isotherm of 60 degrees has a type of carna- 

 tion of its own, adjusted through forty years from the same par- 

 ents to meet different climatic conditions and meets the sesthetical 

 tastes of the people of that climate as fully as does the L,a Puritie 

 type on the isotherm 50 degrees in north latitude. 



In 1892-3-4 there were introduced over one hundred fine 

 named varieties of California carnations into the latitude of the 

 semperflorens type, and it was proven that their modified type was 

 not adapted immediately to the semperflorens zone. Mr. Linton 

 of Piru City, California, says that carnations there are grown out, 

 they live for several years, grow best in their wet or winter season, 

 and bloom best in their dry or summer season; they make a bush 



