GOLDSOHMIDT's monograph of AMPHIOXIDES. 585 



regarded as an accessoi'v organ to the endostyle ; it is well 

 developed in Amphioxides^ opening into the pharynx 

 behind the posterior end o£ the endostyle into the dorsal 

 nutritive portion. Goldschmidt has not found an external 

 orifice of the gland such as was first observed by Hatschek 

 (1881), and subsequently confirmed by Lankester and Willey 

 (1890), and Willey (1891) in the larva of Branchiostoma 

 lanceolatum. 



Now there is a reflection which must occur to the minds 

 of those who may be conversant with the living larvae of 

 Amphioxus, and with the extreme contractility of their 

 tissues, which may raise a doubt concerning the fundamental 

 importance of the lateral ridges of the pharynx of Am phi- 

 ox ides as interpreted by Dr. Goldschmidt. There is not a 

 shadow of doubt that the gill-slits and gill-arches of 

 Amphioxides would wear a very different appearance 

 from that which they present in Dr. Goldschmidt's excellent 

 figures if they were seen fully expanded with the body in a 

 state of turgidity, and it seems not unlikely that under those 

 conditions the projecting ridges ^ of the pharynx would 

 vanish and the folds of the gill-arches straighten out. 



Again, it follows, from the interpretation of facts which 

 has been outlined above, that the anterior dextral position of 

 the endostyle, with its unequal limbs, is also a primitive 

 feature; but Goldschmidt has not observed in Amphioxides 

 those paired ciliated peripharyngeal bands which proceed 

 upwards and backwards from the anterior ends of the endo- 

 style in the larva of Amphioxus, and offer such a striking 

 analogy with the similar organs of the Tunicata. These 

 bands, while distinctly pointing to an affinity with the 

 Ascidians, also indicate that the endostyle, although asym- 



1 These ridges, the so-called limiting folds or plicae limitantes, are 

 described as being lined by cylindrical flagellate cells, the long flagellum of 

 which is connected through the cell-body with the nucleus by a clear and 

 deeply staining rod. It seems highly probable, after all, that they are homo- 

 logous with the peripharyngeal bands of Amphioxus. Forster Cooper also 

 figures them in larvae of Amphioxides taken at the Maldive Islands. 



