142 



SCIENCE 



[N. S. Vol. XLT. No. 1154 



were successful occasioned a large amount of 

 fighting' and confusion on the rookeries in the 

 season of 1913. 



Fortunately, Mr. Hanna has given us the 

 data to illustrate just what this fighting and 

 confusion has meant; he has supplied us with 

 a count of the dead animals. Similar figures 

 for 1915 are not available, but we have such 

 figures for 1912 and they may be compared as 

 follows : 



Animals Dead 1912 igi6 



Bulls 3 12 



Cows 27 79 



Pups 1,060 2,482 



The deaths in 1912 were what might be con- 

 sidered normal and inevitable. In that season 

 there were only 113 idle bulls and the fighting 

 was a negligible factor. The deaths occurred 

 as a result of accidents inherent in the 

 crowded condition of harem life. In 1916, 

 however, we find the deaths among bulls quad- 

 rupled ; among cows, almost trebled and among 

 pups, increased 134 per cent. Moreover, this 

 is with only between two and three thousand 

 idle bulls. What will be the result when the 

 60,000 to 70,000 idle bulls begin six to eight 

 years hence to bring their pressure to bear 

 upon the breeding grounds? 



In my report for 1913 I attempted, without 

 effect, to bring this unfortunate aspect of the 

 fur-seal law of 1912, which could readily be 

 foreseen, to the attention of the Bureau of 

 Fisheries in the following words : 



The bull fur seal is an animal of about 500 

 pounds weight; his mates are animals of 80 pounds 

 weight; the pup at birth is a weak thing of 12 

 pounds. The harem life of the seals is crowded 

 at best and subject to commotion. The mother 

 seal takes no thought of the time and place of 

 labor. Newly bom pups are trampled and 

 smothered under the best of circumstances. Any- 

 thing which creates turmoil and fighting in the 

 vicinity of the breeding grounds is necessarily 

 fraught with danger to the young. Fighting 

 among the bulls arises from attempts by idle bulls 

 to steal cows from their more successful neighbors. 

 In these contests cows are torn and injured and 

 pups trampled. . . . 



George Archibald Clark 



Stanford Universitt, Calif., 

 January 23, 1916 



PROFESSOR CURTIS'S REVIEW OF PETRUNKE- 

 VITCH'S MORPHOLOGY OF INVERTE- 

 BRATE TYPES 



The review of Professor Petrunkevitch's 

 " Morphology of Invertebrate Types " by Pro- 

 fessor W. C. Curtis in Science for December 1 

 is rather misleading. The method of presenta- 

 tion in Professor Petrunkevitch's book is cer- 

 tainly one for which many teachers of inverte- 

 brate zoology have been waiting. Commenda- 

 tion of the principles upon which the book 

 is founded and explanation of the necessity 

 for such a work have been very ably put forth 

 in Professor Curtis's review. However the 

 method of presentation of subject-matter and 

 type forms taken up for consideration are but 

 two of the many points to be considered in 

 determining the value of a book as a text for 

 student use. It has been my experience, and 

 I am sure it is shared by others, that one of 

 the most difficult things to accomplish with 

 the student in science is an appreciation of the 

 necessity for clearness of expression. Mis- 

 takes in grammar and in English are too fre- 

 quently looked upon as of no consequence to 

 the scientist. In view of these facts I feel 

 that the reviewer has omitted some points to 

 which attention should have been called. 



When Professor Curtis makes the remark 

 that " the book is well done, clear, concise and 

 to the point ..." he very evidently does not 

 consider such passages as : 



Place a specimen in a white dish with water on 

 its right side and make a drawing twice natural 

 size showing the left side (page 155). 



On page 8 the student is directed to 

 Label anterior and posterior end, dorsal and 

 ventral surface. 



Another example of what does not appear to 

 be either clear or concise is found on page 39, 

 where the reader is told that 



The circular canal follows the edge of the disc 

 between every rhopalium. 



I do not believe that a zoology text could 

 be written in sufficient detail to eliminate the 

 necessity of a teacher, but I do think that a 

 large percentage of the average undergraduate 

 class in studying the anatomy of Molgula 

 would require an explanation on the part of 



