118 



On DimorpTiism in Prmmla. — Mr. C. Darwin has examined tlie 

 sexual relations of the two forms in the Cowslip, Primrose and other 

 species of Primula, called by florists ' pin-eyed ' and ' thrum-eyed.' 

 The one (pin-eyed) mth the style reaching beyond the anthers to the 

 mouth of the corolla-tube, which is slightly widened above, stigma 

 globular and rough, the pollen-grains small and oblong in form, and 

 perfecting comparatively few seeds : the other (thrinu-eyed) with a 

 short style, and smooth, depressed stigma, falling short of the anthers, 

 pollen-grains spherical, corolla-tube of uniform diameter, and per- 

 fecting a larger number of seeds than the former. 



Between these forms four crosses can be tried : — viz. the stigma of 

 the long-styled form, fertilized by its own pollen and by that of the 

 short-styled, — and the stigma of the short-styled by its own pollen and 

 that of the long-styled form. Fertilization by own-form pollen Mr. 

 Darwin calls ' homomorphic,' by pollen of dissimilar form ' heteromor- 

 phic' Experiment showed the heteromorphie (in which insect agency 

 is absolutely essential) to be much more fertile than the homomorpliic 

 union, in which the forms were as sterile as are many distinct species 

 when crossed. The object of the dimorphic condition Mr. Darwin 

 considers to be to favour the sexual union of distinct individuals of 

 the same species. 



Other similar cases of dimorphism were named in five distinct 

 Natui-al Orders.— i>irtw. Soc. Proc. Nov. 21, 1861. 



A letter, dated Sept. 12, 1861, has been received from Mr. Mann, 

 Botanical Collector to the Eoyal Gardens, Kew, giving an account of 

 his ascent of the Peak of St. Thomas, (7,500 ft.) in the island of that 

 name in the Gulf of Guinea. 



The ascent is described as extremely diflicult. Mr. Maim found 

 a tropical forest vegetation ascending to the very summit. Glei- 

 cheina dichotoma, a shore plant at Fernando Po groAvs upon the top, 

 and Eluis growing in that island only to 1000 ft. was found in St. 

 Thomas to 3000. A Conifer {Fodocarpus) and an Anthocleista were 

 also collected, On Clarence Peak, Fernando Po (10,700 ft.) 55 tem- 

 perate plants were collected by Mr. Mann at and above an elevation 

 of 5000 ft. This indefatigable collector expects shortly to ascend the 

 Cameroon Mountain on the main land (13,000 ft.) 



Note on tlie Hahits of Vipers.— 1\iQ parental instincts of most 

 cold-blooded_ Vertebrata lead them no farther than to deposit their 

 eggs in a suitable locality. As a general rule, we may say of them, 

 in the beautiful words of Job, 



" She leavcth her eggs in the ciirth,— And warmcth them in the dust, 



Porgetting that the foot may crush them,— Or tliat the wild beast may break them. 



blieis hardened against Her young ones,— A,'? tliougli thcv were not liers." 



