242 BULLETIN OF THE 



the egg of Agalma. Haeckel * says that lie made attempts to fertilize 

 artificially the ova of the genera Prai/a, Diphi/es, Abi/la, Ilijipopodius, 

 Athorybia, Agalmo2->sis, llalistemvia, Forskalia, C'rystallodes, and Physo- 

 phora. " Die Mehrzahl der Versuche schlug fehl, und in vielen Fallen 

 gingen die befruchteten und sich entwickelnden Eier zu Grunde. Ehe 

 sie noch iiber die ersten bereits von Gegenbaur beschriebenen Entwick- 

 elungstudien hinaus die Entwickelungsvorgange zu verfolgen, gelang 

 mir nur bei drei Physophoridcn-Gattungen, niimlich bci Physophora (bis 

 zum XXVII P"=° Tage), C'rystallodes (bis zum XXVIP"=° Tage), und bei 

 Athorybia (bis zum VIl**" Tage)." He does not state with sufficient ex- 

 actness in the case of Crystallodes, the nearest ally of these three genera 

 to Agalma, whether he artificially impregnated the ovum or not. 



The natural ovulation in Agalma was the only means of getting mate- 

 rial for the study of the embryology ; and as this happened seldom, even 

 in instances when I had in confinement a large number of large and 

 sexually mature specimens, the amount of material at my control was 

 small. The youngest larvse are very hardy, needing, for early stages at 

 least, no change of water, provided decaying mattet from the adult 

 animal be not allowed to pollute it. 



Each ovum is carried in a bell-shaped structure called the female 

 gnnophore. The female gonophores (PI. I. fig. 1) are found in botryoidal 

 bunches at the base of the polypites, and generally adhere to the neigh- 

 boring hydrophyllium when it is broken from its attachment to the stem. 

 The gonophore is fastened to the axis by its apex, through which a small 

 tube communicates between a system of vessels called the radial tubes 

 and the cavity of the stem. No marginal tube or marginal appendages 

 of any kind were detected on the bell. The course of the radial tubes 

 in the bell of the female gonophore (PI. I. fig. 3) is very irregular, and 

 varies very greatly in different individual gonophores. In a form of 

 gonophore which was common, the following arrangement in the disposi- 

 tion of the tubes was observed. Two radial tubes arise from a common 

 point under the apex of the bell, at the junction of the same with the 

 tube of the apex. These lie in opposite hemispheres on the walls of the 

 bell cavity. Consider the course of one of these radial tubes. After 

 extending from under the apex of the bell about half-way down the 

 sides of the bell on its inner surface, it bifurcates, each division passing 

 at right angles to the course of the undivided tube. Each of the bifur- 



* Zur Entwickelungsgeschichte der Siplionophoren. Eine von der Utrechter 

 Gesellschaft fiir Kunst und Wissenschaft gekibnte Preisschrift. Utrecht, 1869. 

 p. 10. 



