688 



SCIENCE. 



[Vol. II., No. 42. 



advantages to science, both agricultural and 

 to a less extent general, which would result, 

 but because we believe such a course to be the 

 onl_y one which will lead to enduring popularitj', 

 or j'ield gains to agriculture commensurate with 

 the outla_y. We are confident, that, if Dr. 

 Sturtevant will make it his avowed aim to do 

 as much real scientific work as possible, the 

 state will receive a far larger return for its 

 outlaj^ and that within no long time it will 

 acknowledge such to be the case ; while the 

 beneficial eflfects of such a course, in promoting 

 an appreciation of and respect for true science 

 among the people, would not be its least recom- 

 mendation. 



Agricultural experimentation is attracting 

 increasing attention ; and it seems important 

 that a clear idea should be reached hy those 

 concerned in it of its proper aims and meth- 

 ods ; and this can be attained in no better wa}^ 

 than hy a free criticism, on the part of all con- 

 cerned, of methods and ideas which seem to 

 them false or unwise. 



HERRICK'S TYPES OF ANIMAL LIFE. 



Types of animal life, selected for laboratory use in 

 inland districts. JJy C. L. Herrick. Part i., 

 Arlhropoda. Minneapolis, 1883. 33p.,7pl. 8°. 



The author sa}'s in the preface, that the notes 

 which this work contains are only a small part 

 of the material collected some j'ears ago for a 

 ' Laboratory assistant for western students, 

 arranged upon quite a different plan.' Dur- 

 ing the delaj' in completing the proposed work, 

 the great need of it has been in a measure 

 supplied by repent works ; but as these treat 

 chiefl}' of marine forms, or such as require dis- 

 section, he has ' thought best to place at the 

 disposal of students and teachers in summer 

 science classes ' his notes on such tj'pes as can 

 be studied, while living, under the microscope. 

 The types selected are the larva of Corethra, 

 Canthocamptus, and Gammarus, which are de- 



scribed, without directions to tlic student, or 

 explanations of metliods of work. 



A text-book of this kind ougiit to be clearly 

 written, and accurate, a model for the student ; 

 but Mr. Ilerrick's work is far from tliis, and 

 no better than we might expect to find the 

 rough notes of the student in a ' summer sci- 

 ence class.' The description of tiie heart of 

 Chironomus, on p. 7, is throughout almost or 

 quite unintelligible, and ends with the state- 

 ment that ' the last chamber is closed behind, 

 and has the ostia quite a distance be3'ond.' 

 On p. '25 we have the opening of the green 

 or antennal gland of Gammarus described as 

 ' an auditoiy or other sensorj- organ ; ' and on 

 plate 8, an antennula, or first antenna, figured, 

 for comparison, as the ' second antennae of 

 prawn, with auditory sac and secondary flagel- 

 lum.' The Copepoda are Mr. Ilerrick's spe- 

 cialty, and so we naturally turn to the cliapter 

 on Canthocamptus for better work : but in the 

 first paragraph we are told that the Copepoda 

 are divided into three sections, — Gnathostoma, 

 having ' the mouth-organs in the form of jaws ; ' 

 while ' the other sections, Poecilostoma and 

 Siphonostoma, have the mouth-parts more or 

 less modified for piercing or sucking.' The 

 student may search long and unsuccessfuUj' to 

 discover what the ' Poecilostoma ' may be. la 

 this chapter, also, we naturally look for some 

 account of the ' heterogenesis ' of which Mr. 

 Herrick has written elsewhere, and find the 

 following : — 



"The young of Canthocamptus become fully de- 

 veloped sexually before they assume their final form; 

 and it is not unusual to find females bearing egg-sacs 

 which are not only much smaller than the parent, 

 but with considerable differences in the various 

 organs. This sort of heterogenesis is not uncommon 

 among lower Crustacea, for the mother may differ 

 much from the young till after they have themselves 

 produced young." 



Grammatical, verbal, and typographical 

 errors so abound that it is needless to point 

 them out. The illustrations, engraved by the 

 author himself, are for the most part far from 

 accurate, and very rude. 



WEEKLY SUMMARY OF THE PROGRESS OF SCIENCE. 



ASTRONOMY. ' 



Photographing the solar corona -without an 

 eclipse. — Dr. Huggins has continued his experi- 

 ments on this subject during the past season. He 

 has made use of a fine seven-and-a-quarter-inch spec- 

 ulum by the late Mr. Lassell (loaned for the purpose 



by Miss Lassell). Three inches and a quarter of the 

 central portion only are employed, the light being re- 

 ceived a little obliquely, so as to throw the im.age to 

 one side, as in the Herschellian telescope, thus avoid- 

 ing a second reflection. The absorbent screens of 

 potassic permanganate, or blue pot-glass, have been 

 dispensed with, and an emulsion, prepared specially 



