17 



Oxlip, but retaining the orange spots around the throat of the corolla-tuba. 

 This great increase in the number of flowers borne by each plant, I take to be a 

 proof that the species is approaching the lowest limit of its development : just 

 as the human race is most prolific in poverty, and as those races of animals 

 which are most easily destroyed are most fecund — nature making greater efforts 

 as it approaches the danger of extinction. This plant with the large head of 

 richly fragrant flowers is the Cowslip in perfection. The plant seems soon to 

 exhaust the soil of its habitat; and if it stay, or if the wind carry its seed out 

 of the wood or away from the rich sheltered hedgebank into the poorer soil 

 and colder situation of the open meadow, the flowers speedily degenerate in 

 number, and in place of a head of twenty or thirty blooms we have a poor starved 

 plant with two flowers, or even with one. The fields adjoining the western 

 edge of Acornbury wood, on the roadside going to Ross, occur to my memory as 

 one among many places full of specimens of this state of the Primula. 



Experiment, as far as I have pursued it, bears out my theory. I have 

 transplanted some very fine Oxlips from the rich vegetable soil of a wood on 

 clay subsoil to the comparatively poor soil of a cold open spot, and have found 

 them degenerate just in the way in which I have stated. I have not yet tried 

 the experiment in the reverse way, but the case of the garden Polyanthus seems 

 to be just an artificial case of the advance which my theory supposes to occur 

 from natural causes. I have always understood that the way to "improve" 

 that favourite " florist's flower " is enrich the soil with strong manures. The 

 colour of the flowers, for example, I have been told may be darkened very much 

 by the application of street-scrapings in towns to the roots of the plant. 



This remark suggests the whole subject of the colours of the flowers of 

 PrimuL-e, which vary greatly. This season I have had Primroses, all wild, vary- 

 ing in colour from a dead white through pale and deep pink, lavender, and 

 purple of various shades. The natural yellow of the corolla is probably due to 

 alumina, since I find transplanted Primula; in the less clayey soil of a garden 

 lose colour; while the pink— called by Linnfeus incarnatus, or flesh-hued— is 

 attributed to the action of oxygen upon the grains of chromnle, the green 

 colouring matter of the plants ; and the lavender and purple show the combined 

 action in various proportions of oxygen and carbon, the darker hue resulting 

 from the predominance of the latter substance. In all cases when leaves 

 expand, the grains of chromule are surrounded by a thin film of gluten, which 

 is chiefly composed of nitrogen ; and the changes of colour in plants are due to 

 the contest which goes on between the oxygen of the atmosphere and these two 

 elements, the carbon of the chromule and the nitrogen of the gluten. 



The specimen of wild Polyanthus on the table, which is remarkable at once 

 for its resemblance in form and its difference in hue to the Oxlip, was gathered 

 for me by Dr. Bull on the estate of our esteemed President at Harewood. I 

 understood that he obtained it, along with specimens of Primroses of various 

 abnormal hues, from the immediate neighbourhood of the old house of the 

 Knights Templars ; and that fact at once reminded me that the first parpio 



