52 DB, THOMSON ON SEEDS OF BABBIKGTONIA AND CABETA. 



at the extremity from which the stem is afterwards developed 

 surface is perfectly uniform. 



Eoxburgh's MSS. drawings in the library of the Calcutta 

 tanic Garden contain excellent figures of the germinating see 

 Careya arhorea and Barringtonia racemosa. My examinatii 

 the germination of Careya has confirmed Eoxburgh's observat 

 and I found that, allowing for difierence of size and shape 

 germination of JBarringfonia acutangula^ the species I exam 

 is exactly Uke that of B. racemosa^ as figured by Roxburgh, 



In all, the only appearances of foliar organs are a few mi 

 scales surrounding the growing point, which is gradually < 

 gated into the ascending axis. On this 

 quite rudimentary, and true leaves are not developed till it has 

 become one or two inches long. 



A longitudinal section of a germinating plant shows that the 

 central body is continuous with the pith, and the superficial body 

 with the bark, as Boxburgh has long ago stated. It further shows 

 that the vaacular laver, which senarates the two. is continuous 



axis 



and root 



downwards with the ligneo-vascular cylinder 



It is thus evident : 1. That the embryo of Barringtonie<e is ex- 

 albuminous. 2. That the cotyledons are rudimentary. 3. That the 

 embryo is an axial organ, consisting of pith, woody layer, and bark. 

 4. That the plumule, at best almost without scales, is developed 

 into a stem, while the opposite extremity elongates into a root. 



In examining nearly a hundred germinating plants of Ca/reya 



■ 



arborea^ I found that in a considerable number (eight or ten 

 instances) the primary axis died ofi*, and the stem was continued by 

 a bud springing from the axil of one of the minute scales. In one 

 instance this took place so close to the embryo as to be apparently 

 in the axil of one of the first pair of scales, or rudimentary coty- 

 ledons. 



In describing the seeds of Oarcinia and XanthocTiymm ^ Boxburgh 

 states that their structure is quite like that of the seeds of Careya 

 and Barringtonia, except that the central portion (which he calls the 

 embryo) is very slender, and that the permanent root proceeds 

 from the base of the plumule, while that from the opposite end of 

 the embryo soon perishes, or remains slender as compared with the 



other. 



adventitious 



common occurrence also m 



r 



Careya, so that the difference is even less than Boxburgh sup- 

 posed. Circumstances prevented my examining germinating seeds 







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