26 HUGH PRICE. 



which was kept undisturbed for some days. The cut-off 

 hydraiiths were found to attach themselves by the cut end of 

 the hydrocaulus to the sides and bottom of the vessel and 

 to give rise to new colonies. Thin cover-glasses were placed 

 on the bottom of the vessel, and to some of these the detached 

 hydranths affixed themselves, thus giving a means of study- 

 ing the mode of attachment. The cut end by which the 

 animal appears to attach itself is seen under the miscroscope 

 to have given rise to a knob-like swelling, consisting of 

 endoderm and ectoderm. But it is not by means of this 

 knob directly that the hydranth becomes affixed. Delicate 

 filaments, continuovis Avith the horny perisarc are seen ex- 

 tending from the neighbourhood of the knob, and these fix 

 the organism to the glass. The knob, on the other hand, 

 proceeds to point in a direction away from the surface of 

 attachment, and gradually develops a bud, which elongates 

 into a complete hydranth, with a rapidly growing stalk or 

 hydrocaulus. Thus two main stems are united at the point 

 of attachment, viz. that of the original hydranth cut off for 

 experiment and that of the new hydranth which has grown 

 out from the cicatrix or knob. 



Further (at this time of the year and in these particular 

 specimens) there is a great tendency on the part of the 

 proximal segments of hydrocaulus still attached to the 

 colonies from which hydranths have been cut to produce 

 new hydranths. I have even noticed this on old pieces 

 of hydrocaulus overgrown with Vorticellse and Algae. I 

 had occasion to cut a considerable piece off from a main 

 stock, and some of the oldest part of the colony was 

 removed with it. After five days there was developed from 

 the cut end of that portion of the old stalk still attached to the 

 main colony a new hydranth with, about half an inch of new 

 stalk attached to it. 



These observations on reproduction from the hydrocaulus 

 correspond in the main facts with those of Dalyell and 

 Allman on Tubularia, but the production of a new hydranth- 

 bud from the cicatrix-knob of the radical end of a divided 

 hydrocaulus is not recorded in the case of Tubularia. The 

 facts above noted show that Cordylophora is well adapted for 

 the study of some of the phenomena of artificial repro- 

 duction.^ 



1 I may add to these notes that Cordylophora is by no means difficult to 

 keep alive if provided with a veri/ large quantity of water and kept iu the 

 dark. Specimens taken in June are still alive (October). These specimens 

 consist of fragments of a colony numbering only some half dozen hydranths. 

 Each fra.E^ment has been kept in a covered half-pint jar in a dark cup- 

 board. — E. Ray Lankester. 



