March 20, 1908] 



SCIENCE 



453 



with black, forming "green" patches of 

 variable extent. The behavior of the 

 plumage color in subsequent generations 

 supports the view that the gametic formula 

 of the "green" canary is: Nm [i. e., black 

 (nigrum) pigment present, mottling ab- 

 sent] and .that of the yellow canary is nM 

 {i. e., black pigment absent; mottling 

 factor present]. Hybrids between the 

 goldfinch and canary show, in the same 

 way, the presence of the mottling factor; 

 but the dark patches are usually extensive. 

 The "reversionary" character of the 

 hybrid is due to the original pattern of the 

 wild canary that lies latent— because of 

 lack of pigment, in the yellow canary. 



The Sense of Taste in Fishes: G. H. 



Paeker, Harvard University. 



In the common horn pout {Amiurius 

 nehulosus) taste buds occur not only in the 

 mouth and on the barbules but also over 

 almost the whole external surface. Those 

 on the exterior of the fish are innervated 

 by branches of the seventh nerve. Horn- 

 pouts will snap at a bait when it is pre- 

 sented to the flank of the body as well as 

 when it is close to the mouth. The ex- 

 terior of the body is also sensitive to sour, 

 saline, and alkaline solutions, the head 

 being more sensitive to these solutions than 

 the trunk. In horn-pouts in which the 

 branch of the seventh nerve distributed to 

 the skin of the trunk has been cut, thus 

 rendering inoperative the taste buds of the 

 trunk, there is no longer a response to bait 

 brought near the trunk, though the same 

 bait is greedily taken when presented to 

 the mouth. Such animals, however, retain 

 their full sensitiveness to sour, saline, and 

 alkaline solutions when applied to the skin 

 of the trunk. That the loss of response to 

 a bait when presented to the flank of a 

 horn-pout after the severance of the 

 seventh nerve is not due to shock is shown 

 by the fact that this sensitiveness is re- 



tained by fishes in which the large lateral- 

 line branch of the tenth nerve has been cut. 

 After cutting the lateral branches of both 

 the seventh and tenth nerves the only sen- 

 soi'y nerves left intact on the flanks of the 

 body are the branches from the spinal 

 nerves. Since fishes in this condition re- 

 spond to sour, saline and alkaline solu- 

 tions, it follows that these solutions must 

 stimulate the terminals of the spinal nerves 

 and that these nerves must be regarded, 

 therefore, as chemical in function, though 

 they are not primarily concerned in the 

 response to bait. In hom-pouts the pos- 

 terior half of whose spinal cord has been 

 destroyed but whose seventh nerve is in- 

 tact, there is no response when sour, saline, 

 and alkaline solutions, and bait are ap- 

 plied to the flanks near the tail. The ab- 

 sence of response to bait in this experiment 

 is due, I believe, to the loss of the motor 

 mechanism of the cord whereby the fish 

 turns to snap at the bait and not to the 

 loss of the spinal sensory fibers. The loss 

 of these fibers would account for the ab- 

 sence of response to sour, saline and alka- 

 line solutions. From these experiments it 

 is to be concluded that the sense of taste 

 in horn-pouts is complex and involves not 

 only the seventh nerve, but also the spinal 

 nerves. 



The Organ of Glaus in the Copepod Eu^ 

 calanus elongatus Dana: C. 0. Esteklt. 

 E. L. Mark gave an account of some of 

 the principal points regarding "The 

 Organ of Glaus in the Copepod Eucalanus 

 elongatus Dana" which have been dis- 

 covered by Dr. CO. Esterly. There is a 

 pair of these organs, and they are im- 

 bedded in the front part of the brain near 

 its ventral surface. Glaus, who discovered 

 the organs in E. attenuatus Dana, thought 

 they were otocysts. Esterly shows that 

 they are not vesicular, but are solid, each 



