Dr. C- Chun on the Siphonophora. 159 



their appearance on this little stem quite close to the tiuid- 

 receptacle, and, indeed, first of all a bad of considerable size 

 above (towards the apex of the umbrella), and afterwards, 

 opposite to this, a group of four buds (tig. 5). While the 

 first developed bud, as soon appears to be the case, represents 

 the rudiment of a nectocalyx, we are struck, in the group of 

 four buds, with a development identical with that of those groups 

 of buds which we have already had occasion to mention on the 

 basal part of the stem of Muggicea. In point of fact we 

 cannot avoid the notion that the four buds represent the con- 

 stituents of a Eudoxia Eschscholtzii, the stomachal sac, the 

 tentacle, the bract, and the genital calyx. 



But how are we to explain the enigmatical phenomenon 

 that, by two so perfectly different forms as are represented by 

 the Muggicea and Monophyes primordialis, there are formed 

 bud-rudiments which perfectly harmonize in their further 

 development, and in both cases grow up into Eudoxia Esch- 

 scholtzii? The solution of all the problems which thus press 

 themselves upon us is no less surprising. From the rudiment 

 of a nectocalyx placed at the origin of the stem of Monophyes 

 pnmordialis is produced the five-angled nectocalyx of the 

 Muggicea. Muggicea Kochii consequently does not represent 

 a distinct species, but it is produced by gemmation from -Mo- 

 nophyes primordialis, and then y carrying with it the par^it 

 stem and the future EiXidoxisL-g roups, separates from the parent 

 animal and leads a free existence. In fig. 4 I represent a 

 stage (captured in freedom) which clearly demonstrates the 

 connexion between Muggicea and Monophyes. The nectocalyx 

 of the former has already acquired the pentagonal form, and 

 shows distinctly the characteristic course of the vessels. The 

 aperture of the calyx is turned away from that of the Mono- 

 phyes-calyx, so that the two perform brisk pumping move- 

 ments in opposite directions. In almost all the subsequently 

 observed cases (and by rearing the Monophyes I have six times 

 succeeded in getting the calyx of the Muggicea to grow to 

 half the size of the Monopkyes-calyx) the calyces were ar- 

 ranged in the same direction. The stem is already of consi- 

 derable length, and, besides the terminal stomachal sac with 

 the tentacle, shows the rudiment of another Eudoxia -group. 

 But if we place the organism in a watch-glass with abundance 

 ot water and observe the two calyces engaged in performing 

 their very lively pumping movements, we sometimes succeed 

 in directly convincing ourselves of their separation, inasmuch 

 as generally after a violent pumping movement on the part 

 ot one of the calyces the delicate uniting part of the stem tears 

 away, and the two then continue to move independently. 



