MORPHOLOGY AND DEVELOPMENT OF EUDENDRIUM. 45 



in the young and sexually mature colonies as shown by their his- 

 tological condition. In the former there is enough food not only 

 for the hydranth and the rapidly growing cambium tissue at the 

 ends of the pedicels, but for the small requirements of the cceno- 

 sarcal column down to the very base of the colony. In the lat- 

 ter, the rapid growth of the eggs must cause the absorption of a 

 greater proportion by the hydranths and the pedicels of ortho- 

 spadiceous gonophores. The tissue farthest removed from the food 

 supply is the ectoderm of the coenosarc. It is also least necessary 

 to the economy of the colony at this period of its life. Accordingly 

 we find it undergoing retrogressive change in mature colonies at 

 the same time when gonophores are vigorously developing. The 

 last part of the cosnosarc to cease its activity is the cambium 

 tissue, close to the hydranths. 



LITERATURE. 

 Allen, C. M. 



'oo A Contribution to the Morphology and Development of Tubularia crocea. 

 Biol. Bull., Vol. I., p. 291. 



Allman, J. G. 



'63 Reproductive System in Hydroida. Proc. Brit. Assoc. Adv. Sci. 



Bourne, A. G. 



'83 Recent Research Upon the Origin of the Sexual Cells in Hydroida. Quar. 

 Jour. Micr. Sci., Vol. 23, p. 617. 



Braem, F. 



'94 Ueber die Knospung bei mehreschichtigen Tieren in besondere, bei Hydroi- 

 den. Biol. Cent., Bd. XIV., p. 140. 



Brauer, A. 



'91 Ueber die Entstehung der Geschlechtsproducte und die Entwicklung von 



Tubularia mesembryanthemum. Zeit. Wiss. Zool., Bd. 52, S. 55 * 

 '91 Ueber die Entwicklung bei Hydra. Op. cit., Bd. 52. 



Brooks, W. K. f 



'88 On a New Method of Multiplication in Hydroids. J. H. U. Circulars, Vol. 

 VII., p. 29. 



Bunting, M. 



'94 Origin of Sex Cells in Hydraxtinia and Podocoryne. Jour. Morph., Vol. IX. 



Ciamician, J. 



'79 Ueber den Feinern Lau und die Entwicklung von Tubularia mesembryanthe- 

 mum. Zeit. \Viss. Zool., Bd. 32, S. 332. 



'78 Zur Krage die Entstehung der Geschlechtsstoffe bei den Hydroiden. Op. 

 cit., Bd. 30, S. 50. 



Doflein, F. J. Th. 



'96 Die Eibildung bei Tubularia. Zeit. Wiss. Zool., Bd. 62, S. 61. 



