222 CLARKE^ ON STRIPED MUSCULAR FIBRE. 



one of tlie vessels. In a few days afterwards a considerable 

 nviraber of planuljB were found in this vessel alone, and were 

 carefully removed with a glass syringe into a small vessel of 

 filtered sea-water. Of these, two affixed themselves to the 

 side of the vessel, and developed each a disc, branching into 

 four symmetrical lobes, spreading over the glass. From the 

 juncture of these lobes sprung the polyp-stalk, which put forth 

 the polyp from its summit. 



The polyp of T. inconspicua resembles very closely Cam- 

 panularia raridentata, Alden, the stalk being ringed at its 

 root and again just beneath the cell ; the cell toothed Avith 

 seven denticulations. The polyp, with a trumpet- shaped 

 mouth and fourteen alternating tentacles. 



After a few days one of the lobes attached to the glass of 

 one of the young zoophytes began to enlarge, and extended 

 itself into a creeping fibre, from which a second polyp-stalk 

 sprung. This stalk was crowned with a cell having nine 

 denticulations, and its contained polyp had eighteen ten- 

 tacles. The other young zoophyte also put forth a creeping 

 fibre and second polyp in like manner, but its cell had only 

 seven teeth and its polyp fourteen tentacles. At this stage 

 both specimens died. In the meantime the planulse in the 

 larger vessel had covered the side of the vessel with a great 

 number of young zoophytes, but none of these put forth a 

 second polyp"^. 



On the Development of Striped Muscular Fibre in Man, 

 Mammalia, and Birds. By J. Lockhart Clarke, F.R.S. 



In pursuing the histological investigations which form the 

 subject of the present communication I have endeavoured to 

 discard from my mind every kind of theoretical bias, and to 

 record only what was actually experienced as the results of 

 purely practical observation. The drawings are not intended 

 to illustrate any interpretation of what was observed, but are 

 faithful representations of the objects seen, and served for the 

 following descriptions, which will be as concise as the nature 

 of the subject will permit. The tissues obtained for examina- 

 tion were used in a perfectly fresh state, and with the addition 

 only of water or dilute glycerine. I shall begin with the 

 muscular fibre of the bird. 



* See " Notes and Memoranda." 



