On SheU-groioth in Gephalojpoda. 421 



the world, and find in every instance only three tentacles 

 present, and always similarly located. One is at the poste- 

 rior end of the slit at the junction of the two margins just 

 over the anus, and I believe would be protruded from the last 

 open perforation, or, in other words, that most remote from 

 the lip of the shell. The second is situated well forward on 

 the left margin of the slit, and doubtless would, when the 

 animal was living, occupy the last-completed opening. The 

 third is on the right margin somewhat further back, and, 

 judging by the distance which separates it from the preceding 

 tentacle, probably would be extruded through the second 

 perforation. 



Phili]Dpi, in his ' Handbuch der Conchyliologie ' (p. 215), 

 states that the animal thrusts through the holes the tentacular 

 prolongations of the left side of the foot. This, however, is 

 an impossibility, as the examination of any species at once 

 shows, and possibly was merely a conclusion derived from 

 the appearance of Cuvier's or some other figure. 



LVIIL — Professor Blake and Shell-growth in Cephalopoda. 

 By F. A. Bathek, B.A. 



In the ' Annals ' for April (p. 298) a paper on shell-growth 

 in Cephalopoda was published, in which I described certain 

 facts that appeared inconsistent with the views of Dr. Riefstahl 

 and others. From facts first published by Drs. Riefstahl 

 and Appellof, but verified and extended by my own observa- 

 tions, I ventured to draw a few conclusions and to suggest an 

 explanation which was avowedly theoretical. Prof. Blake 

 (' Annals,' May, p. 376) has been good enough to criticize 

 my paper "without delay. Unfortunately misconception on all 

 sides necessitates a reply. His remarks dealing with ques- 

 tions of priority and trustworthiness must be kept distinct 

 from those dealing with facts and the conclusions based 

 thereon. I first reply to the former ; for if a man is proved 

 ignorant of previously published results and guilty of substi- 

 tuting fancy for fact, his credit as a scientific worker is 

 destroyed. 



There is no doubt that readers of Prof. Blake's article 

 understood him to mean that, so far as facts were concerned, I 

 had said pothing new. This they inferred from such sentences 

 as ''Nor do I find that these writers have anything definite to 



Ann. & Mag. N. Hist. Ser. 6. Vol. i. 29 



