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13. Gemmation . — This is an intricate and difficult branch of the 
subject, for very little appears to be known about the initiatory stages of 
Haly sites ; and I regret that the Australian species do not assist in a solution 
of the problem. Lindstrom, in 1873, seems to have been the first, so far as 
I can gather, to refer to the early stage of this coral. He compared 1 its 
commencement to that of Ileliolites, and said — “ Prom the coenenchyma 
[? mesopore] which is formed on one side of the first calyx, a new calyx is 
produced, and beside this another one, so that one can say that Halysites is a 
Heiiolithid, in which the calices form a line with one another, and not round 
each other. With full-grown and large Halysites colonies, the budding takes 
place in the same way, calices grow out of the coenenchyma as in the 
Heliolithids.” 
I cannot find any reference on this important matter by Nicholson in 
his work, £: Tabulate Corals of the Palaeozoic Period but in the last edition 
of the “ Manual,” 2 he states that increase takes place by “stolonal gemmation.” 
According to the late Prof. P. Roemer, 3 the first condition of growth was 
unknown at the time he wrote. If I understand his remarks rightly, he 
believed that cells arose on opposite sides from a mother-cell, further 
propagation taking place by lateral budding ; this is not far removed from 
the previously expressed view of Lindstrom. 
The observations of Pocta are of importance, as he appears to foreshadow 
a dual form of budding, such as I believe to exist, as well as a modified form 
of earlier stolonal gemmation. Pocta says: 4 “Reproduction is effected by 
lateral budding. Upon the mother-cell there rises a bud with a circular 
section ; the latter becomes elliptic, when the corallite unites with a 
neighbouring new cell Budding may take place, not only on 
the narrow margin of the cell, but also on the broad [i.e., lateral] side. Upon 
the former, the new corallite continues the range [i.e, chain of corallites] ; 
on the other hand, upon the latter it forms the commencement of a new 
ribbon [i.e., chain of corallites], which extends by the further addition of new 
cells.” 5 I take it that his cole etroit (which I have translated narrow margin) 
refers to the mesoporal or cross- wall, transverse to the line of growth ; and so 
his cote large, I have rendered lateral margin. This can only refer to the 
1 Lindstrom, (if vers. K. Vet.-Akad. Forhandl. Stockholm, 1873, No. 4, p. 16. 
2 Nicholson, Manual Pal.. 3rd edit., 18S9, p. 339. 
3 Roemer, Lethoea Pal., 2 Lief., 1883, p. 4S4. 
4 Potta, Barrande’s Syst. Sil. Boheme, VIII (ii), 1902, p. 274. 
5 Pocta, Barrande’s Syst. Sil. Boheme, VIII (ii), 1902, p. 274. 
