Mr. K. Q. Coiicli on till' MurjiLuluyy of Zoophytes. 101 



XXII. — On the Morpholoyy of the different Orqans of Zoophytes. 

 By K. Q. Couch, M.K.C.S.L.* 



[With a Plate.] 



The subject which I have to bring under the notice of tlie So- 

 ciety today is, if it proves true, one of great beauty and unusual 

 interest, inasmuch as the lowest forms of animal life will in the 

 development be found to be governed by the same laws that 

 govern the growth of Howering plants. The vegetable law Ui 

 which I refer is the metamorphosis of the leaf into the various 

 organs which constitute the perfect plant. This law is now so 

 well established and so generally allowed that nothing is required 

 to be said of it ; on the present occasion I sliall therefore proceed 

 to discuss its application to the animal kingdom. To Professor 

 E. Forbes belongs the merit of tirst promulgating the theory of 

 the morphology of the reproductive system of the Sertularian 

 Zoophytes and its analogy with the reproductive organs of flow- 

 ering plants. This he did at the late meeting of the British As- 

 sociation held at Yorkf. It is an o})iuion I have long enter- 

 tained, and in elucidation of \Ahich 1 have for some time been 

 examining almost all the species found on our shores. The views 

 were so new that I hesitated to adopt them, and had I not found 

 that they were held and published by others, I should not now 

 have brought them before this meeting. I do so to show how far 

 the theoiy of Professor E. Forbes is supported by inductive ob- 

 servations ; and that though we pursued in a great measure dif- 

 ferent paths, we yet arrived at similar conclusions. As Professor 

 Forbes confined his observations to the genera Sertularia and 

 Plumularia, they are the ones which will be referred to here, 

 though the same observations may be extended to several genera 

 of the Ascidian Zoophytes; Crisia and Cellularia for instance. In 

 making these observations I shall refer to their grow th ah ovo, and 

 trace the different parts through their development to the fully 

 foraied character. These creatures resemble plants in their aj*- 

 borescent appearance, rooted character, and the transient nature 

 of their reproductive organs. The Sertularian genera have an 

 external horny, elastic and irritable sheath, and this incloses a 

 central gi-anular pulp which extends into all the ramifications and 

 from which all the other parts are formed. On the branches are 

 numerous variously shaped and variously arranged cup-like cells ; 

 but their arrangement and shape are always alike in the same, 

 but different in chfferent species. These are the polype cells, in 



* Read before the Natural History Society of Penzance, Dec ,3, 1S44, and 

 communicated by the author. 



t As reported in the Athenjeum. The entire paper, illustrated by a plate, 

 was inserted in our Number for December 1844. 



Ann. ^ Mag. N. Hist. Vol. xv. N 



