1006 



SCIENCE 



[N. S. Vol. XXV. No. 652 



I found the moutli parts to be a perfect mine 

 of stings. In all fifty were extracted, more 

 than forty of which were imbedded in the 

 flesh adherent to the jaw cartilages. These 

 stings varied in size from perfect sx)ecimens 

 four or five inches in length to broken-oil tips 

 hardly more than one inch long. These 

 broken-off stings were especially abundant at 

 the angles of the jaws where as many as three 

 or four tips were frequently found in a cube 

 of flesh one inch square and two inches long. 

 One can only conjecture how many could have 

 been found by a careful dissection of the flesh 

 of the mouth and throat. The dissection of 

 the jaws was not gotten at until about forty 

 hours after the capture of the shark and its 

 condition consequently was such as to prevent 

 the minute dissection necessary to extract all 

 the spines in the throat region. The lower 

 jaw cartilages were scarred and ridged from 

 angle to symphysis, evidently by stings re- 

 ceived in former combats. Some of the stings 

 were manifestly but newly implanted, for the 

 flesh around them was still red from con- 

 gested blood, in other cases the redness had 

 all disappeared, while some of the stings were 

 plainly old, being imbedded in cysts. Espe- 

 cially was this latter condition true of those 

 piercing the membrane surrounding the car- 

 tilages. 



Not knowing that anything has been dis- 

 covered as to the especial food of the hammer- 

 head shark, I wish to advance the suggestion 

 that this is to a certain degree made up of its 

 not far distant kinsman, the sting-ray. This 

 suggestion is based on three facts. First, that 

 this shark was chasing sting-rays when har- 

 pooned, and was so eager in the chase that, 

 when the first ' iron ' pulled out, it kept up the 

 chase in the neighborhood of the boat until 

 harpooned a second time. Secondly, on the 

 finding of the skeletal remains of rays in its 

 stomach. The whole skeleton of a long-tailed 

 ray found there seems to prove that the re- 

 mains were not those of the butterfly ray 

 (Pteroplatea maclura), which is abundant at 

 Beaufort, but of Dasyatis say, the most com- 

 mon armed form. Thirdly, the very large 

 number of stings found in and around ths 

 mouth parts indicates the number of rays 



which this shark caught and which had been 

 successful in stinging it. 



Since writing the above paragraph, my at- 

 tention has been called by Dr. Theodore Gill 

 to a note by Dr. Edwin Linton in which the 

 latter states that from dissections of fifteen 

 small specimens of another species of the same 

 genus of shark, Sphyrna tiburo, at Beaufort, 

 he found that the food consisted chiefly of 

 Crustacea — blue crabs. Mantis and other 

 shrimps, and acorn barnacles — of seaweed, and 

 of pieces of fish used for bait; but not of 

 whole fish such as they might be expected to 

 prey upon.^ 



E. W. GUDGER 



State Nobmai College, 

 Geeensboeo, N. C, 

 January 24, 1907 



DO OFFSPRING INHERIT EQUALLY FROM EACH 

 PARENT ? 



The alleged fact that offspring inherit 

 equally from each parent, together with the 

 striking parity, in number, size and form, 

 between the chromosomes of the mature male 

 and female germ cells, notwithstanding the 

 great disproportion in size between the egg 

 and the spermatozoon themselves, is frequently 

 advanced as one of the strongest supports of 

 the chromosome theory of inheritance. 



But do we inherit equally from each parent ? 

 What seems obvious at first glance becomes 

 very doubtful upon closer inspection. The 

 vast majority of the characters of a given 

 organism, such, for example, as make it an 

 animal and a vertebrate of a given genus and 

 species, are obviously characters which are 

 common to both parents. The only characters 

 which we can measure are the minor ones of 

 individual or specific peculiarity, and while 

 these, apparently, may be derived equally frona 

 either parent, this conclusion is very different 

 from one which would aifirm that the quali- 

 ties of the offspring as a whole are derived 

 equally from each parent. The hybridist can 



' These observations were made while I was act- 

 ing as a temporary assistant in the Fisheries 

 Laboratory at Beaufort. For permission to pub- 

 lish them here, I wish to thank the Commissioner, 

 Hon. George M. Bowers. 



