48 W. G. RIUBWOOD. 



axes only) is considerably longer* than wide (text-fig. 9, A, p. 27), and when 

 four pairs of plumes are recognisable the same relation holds (text-fig. 9, B). In 

 the adult, however, the antero-posterior diameter is only slightly greater than the 

 maximum width (text-fig. 9, C). In C. dodecalophus the width is a little greater 

 than the antero-posterior diameter (text-fig. 17, F, p. 54). In buds of C. nigrescens 

 the width of the hinder lolje is less than that of the front lobe, but in adults it 

 may be wider or narrower than the front lobe, or equal to it in width. The 

 distance from the centre of the red line to the anterior edge of the shield is in 

 young buds about twice the distance from the red line to the posterior edge. In 

 adults the proportion is 2j times or 2|. 



The stalks of buds of medium and large size are found in various degrees of 

 contraction and extension, and even the same stalk may in one place be thin and 

 smooth, and in another stout and transversely wrinkled. The stalks are so exten- 

 sible in half-grown buds that these buds may l)e found entangled among the 

 plumes of the parent individual, or may even project beyond. The stalks of such 

 l)uds are of course greatly attenuated. 



Before severing its connection with the parent stolon, a large bud usually 

 develops, at the side of the extremity of its stalk, a bud of its own, so that if the 

 parting occurs at the extremity of the stalk (which is not always the case), the 

 stalk has now to be regarded as the stolon of the liberated bud, with the first of 

 its series of buds already present. 



The bases of the bud-stalks of an individual with several buds are disposed 

 more or less in a circle around the hemispherical termination of the stolon, or 

 slightly to one side of it. The order of sequence of the buds is not easy to trace, 

 but it is not unusual to find small buds alternating with large buds around the 

 circle. Figs. 69-75, plate 7, show the appearance of the end of the parent stolon 

 after the stalks of the larger buds have been unravelled, and cut close to their 

 origins. 



A feature of especial interest, as pointing to the possibility of the recognition 

 in the stolon system of Cejyhalodiscus of such a system of branching as occurs in 

 Rliahdopleura, is the occurrence — rare, it is true — among the buds at the end of 

 the parent stolon of a sausage-shaped piece which at its free end has a rosette of 

 buds of its own (figs. 69, 71, 73). In buds half-grown and older the stalk, as 

 has already been noted, may be slender and attenuated in parts, while short and 

 transversely wrinkled in others. These latter parts are sausage-shaped, and 

 pinched at one or both of their extremities, and the most plausible explanation of 

 the above double rosette of buds seems to be that a full-grown bud may sever 

 its stalk at any point, and that not only does the free extremity of that part of 

 the stalk which remains attached to the liberated bud possess the capacity of 

 developing buds of the next generation, but the free end of the other portion 



* For comparisons of this kiinl the shield is removed and mounted for examination under the microscoije. 



