PATTERN OF BUDDING 335 



Some differences, not very great, exist between the seven cormidia of the main zone. It has already 

 been pointed out that cormidium I is the most expanded (PI. XV, fig. 4); cormidium II (PI. XVI, 

 fig. 4) is atypical because of the predominance of its main tentacle and in the absence of the reduced 

 first group (see page 331) so characteristic of cormidia III— VII ; cormidia III-V are the typical ones 

 (PI. XII, figs. 3, 4). In cormidium VII there is a secondary oral branch of groups at the base of 

 group i as just mentioned. It is next to the basal internode between the two zones, where again 

 there is room for the cormidium to expand, and it seems homologous with the regular series of 

 secondary branches, met with in all mature cormidia (described under (4)), which spring normally 

 from the bases of the peduncles of the second or third and fourth or fifth lateral groups. All these 

 secondary branches of groups are shown in Text-fig. 12. 



The degree of complexity which is brought about through the budding of secondary and subsequent 

 series of basal buds is illustrated in PI. XVI, figs. 1-4 of cormidium II of a left-handed 10-in. specimen, 

 number Lanzarote 2. Figures 2, 4 are views from the aboral end. In figure 3 a black bristle 

 indicates the position from which were cut the terminal, lateral groups 5-12, which curled over from 

 left to right of the picture. Figure 1 is a view from the oro-lateral side of the cormidium. Before 

 this photograph was taken a complex basal branch (Text-fig. 17 a) had been cut off. This branch A 

 consisted of six branchlets (Text-fig. 18). The first five of these were single tripartite groups, of which 

 only the gonodendra remained. From the base of the fifth was budded a tertiary branch of five groups. 

 The sixth branchlet (PI. XVII, fig. 1) consisted of six groups. So that from this one basal branch A had 

 been budded seventeen tripartite groups. After the photograph (PI. XVI, fig. 1) had been taken a 

 second basal branch was cut off (Text-fig. 17B). This branch B consisted of thirteen groups. Another 

 branch C (Text-fig. 17) was left intact and bore nine groups. At the base of group 2 of the main series 

 of laterals of this cormidium II (Text-fig. 17D) is another complex basal branch D, whose number of 

 groups is at least 16; and from the base of group 4 of the same main series of laterals of cormidium II 

 is a still further branch carrying six groups. Both group 4 and its basal branch are shown in PI. XVI, 

 fig. 3 to the left of the bristle, and lying on a small rectangular piece of black paper. The basal branch 

 is the uppermost of the two. 



So the secondary and subsequent basal branches of cormidium II, which lie to leeward, had given rise 

 by budding to at least sixty-one tripartite groups. 



Further illustrations of this complex secondary cormidial budding will be found in the figures of 

 cormidium III of the same specimen, Lanzarote 2 (Pis. XVII, XVIII). The first two (PI. XVIII) 

 show the cormidium viewed from opposite ends, and the rest show the severed branches, with 

 indications of the positions from which they were cut. Figures 2 and 4 show the severed aboral branch 

 and PI. XVII, figure 3 shows the branches remaining in situ more clearly displayed. This photograph 

 was taken after severing the terminal laterals 5-1 1 , further magnified in figure 4. 



A final re-examination was made of the two dozen young specimens measuring from 1 to 9 cm. 

 float-length. They included a fine series of fifteen of the specimens sent me by Miss Dodge from 

 Miami. The object of the re-examination was to make sure of the number of cormidia at the aboral 

 end of the main zone. Some doubt had arisen whether there were two or only one anterior to the 

 cormidium bearing the main tentacle, cormidium II, because of the condition found in one of 

 Miss Dodge's specimens, number K 2 (PI. VIII, figs. 5, 6, Text-fig. 19). 



In every specimen of Physalia that I have examined, with the exception of K 2 just mentioned, it 

 could be seen quite clearly that anterior to cormidium II there is a series of distinct tripartite groups, 

 numbering in later stages a dozen or more, and that they obviously form a single cormidium, 

 number I. The criterion is whether the first group of cormidium I is a simple tripartite, or whether it 

 buds off a series of lateral groups. 



5-2 



