Cockayne. — Development of Seedlings. 269 



of Campanula rotundifolia, with its stalked cordate shade 

 leaves, which are at the same time hereditary, and its sessile 

 lanceolate leaves, which are an adaptation to excess of light ; 

 and it may well be that the sessile linear leaves of our plant 

 are due to the strong illumination it must often experience in 

 its exposed station. 



The elastic stem, pale glaucous-green leaves, and early 

 succulence of the seedling show how hereditary are some of 

 the most striking peculiarities of shingle-slip plants. The 

 colour of the leaves, for instance, is the forerunner of that 

 curious grey colour, almost identical with that of the shingle, 

 which nearly all the true shingle-slip plants possess. 



When the cultivated seedlings have had the growing-point 

 of the stem removed there has always been a rapid response 

 in the growth of shoots from the axils of the cotyledons. 

 This in a state of nature would be of great benefit to the 

 plant ; and damage to the growing-point, to which I should 

 imagine wild seedlings are very liable, would be distinctly 

 an assistance rather than a harm to the plant, by encouraging 

 spreading growth. 



Nos. 813 and 966. Gaya lyallii, Baker, var. ribifolia,* 

 T. Kirk. Plate X., figs. 5-10, and Plate XII., fig. 46. 

 The seed of No. 813 was collected near the foot of Mount 

 Torlesse on the 31st March, 1899, at an altitude of 730 m.,. 

 and that of No. 966 in the Trelissick Basin, at about the same 

 altitude, towards the end of April, 1900. I possess no exact 

 details as to the sowing and germination of No. 813. A part of 

 the seed germinated in the spring of 1899 ; a few more plants 

 appeared in the autumn of the same year ; and, finally, in the 

 spring of 1900 about ten more seeds germinated. No. 966 

 was sown on the 21st August, 1900 ; it commenced to ger- 

 minate on the 17th September, 1900, and by the 11th Octo- 

 ber there were in the pot more than thirty plants of different 

 sizes and germination was still proceeding, while by the 

 1st November the tallest plant was 3 cm. in height, and its 

 1st leaf was fully developed. 



Description of Seedling. 

 Early development : By the time the cotyledons enclosed 

 in the seed-coat, and usually also in the remains of the carpel, 

 are just bursting through the ground the root and hypocotyl 

 have developed considerably, and are almost indistinguishable 

 except for the dense mass of very short hairs on the former. 



* This form was first called attention to by Baron Von Mueller in his 

 "Vegetation of the Chatham Islands," Melbourne, 1864, p. 11: "A 

 curious variety of Sida lyallii, with small deeply iDcised leaves, collected 

 by Mr. Travers and Dr. Haast in Middle Island, may be distinguished as 

 var. ribifolia." 



