LITERARY NOTICES. 



701 



occur only in one or the other, and can not 

 survive any diminution or increase of the salt- 

 ness of the water they live in. The simple 

 reason of this phenomenon is the fact that the 

 life of an animal depends not merely on the in- 

 fluence of the external conditions, but on the 

 reaction of its own organizaiion. If we transfer 

 a stickleback directly from fresh to salt water, 

 and leave it there for days or weeks, it will not 

 perish if it be supplied with sufficient food. But, 

 if at the same time we place one of the common 

 fresh-water mussels in sea-water, it will soon 

 die, sometimes in a few hours. The remarkable 

 diflference in the behavior of these two creatures 

 is easily explained by the following hypothesis : 

 In both animals the salt water is transmitted 

 through the skin to the tissues of the body ; 

 but this takes place to a much greater extent in 

 the mussel than in the flsh, and thus injures it, 

 while the flsh can bear the same quantity of salt 

 it has absorbed. If our migratory fishes, as the 

 salmon, had as great an affinity for the salt of 

 the sea-water as the mussels have, they would 

 soon cease to exist, or would have to become 

 adapted to live wholly in fresh water. Thus 

 every change in the conditions of existence in- 

 fluences diff'erent animals in different ways. The 

 problem, then, is to investigate more accurately 

 these different effects of changed conditions. 



Professor Semper's twelve lectures be- 

 fore the Lowell Institute form the twelve 

 chapters of his book. The considerations 

 here presented are put forward in the first 

 or introductory chapter, in which he defines 

 his point of view, and the plan of the dis- 

 cussion. The work is divided into two parts, 

 the first being devoted to " The Influence of 

 Inanimate Surroundings," and the second 

 to " The Influence of Living Surroundings." 

 Chapter II takes up " The Influence of 

 Food " ; III, " The Influence of Light " ; IV, 

 " The Influence of Temperature " ; V, " The 

 Influence of Stagnant Water " ; VI, " The 

 Influence of Still Atmosphere " ; VII and 



VIII, " The Influence of Water in Motion " ; 



IX, " Currents as a means of extending or 

 hindering the Distribution of Species " ; 



X, "A Few Remarks on the Influence of 

 Other Conditions of Existence " ; XI, " The 

 Transforming Influence of Living Organ- 

 isms on Animals " ; XII, " The Selective In- 

 fluence of Living Organisms on Animals." 

 Appended to the volume are sixty pages of 

 valuable notes, followed by a copious alpha- 

 betical index. 



Annual Report of the Chief of Engineers, 

 United States Army. Pp. 264. 



The report describes what was done dur- 

 ing the year ending June 30, 1880, and what 



was needed to be done for the seacoast and 

 lake frontier defenses of the country, and 

 for the improvement of the rivers and har- 

 bors of the whole country ; and records the 

 progress of the special work and of the sur- 

 veys assigned to the corps of engineers. 

 Several maps of Pacific States and of the 

 survey of the Mississippi River, and lake 

 charts, have been published, and an outline 

 map of the territory west of the Mississippi 

 River, on a scale of ^Tju^triju, ia in prepara- 

 tion. 



Life and her Children ; Glimpses of Ani- 

 mal Life from the Am(Eba to the In- 

 sects. By Arabella 13. Buckley, New 

 York : D.'Appleton & Co. ISSO. Price, 

 $1.50. 



After light came life, and with that life 

 there came its two great functions growth 

 and development. With the simplest as 

 with the most complex forms there is the 

 same eager race to be run, to increase in 

 size, to multiply, and, thus replenishing this 

 earth, to die. '' Life and her Children " is 

 a praiseworthy and admirable attempt to 

 tell us something of the Children that Life 

 sends forth, and of their history. Its main 

 object is to acquaint young people with the 

 structure and habits of the lower forms of 

 life ; but in our deliberate judgment it will 

 do a great deal more. None will read its in- 

 troductory chapter without advantage, and 

 few will read the volume through without 

 enjoyment. Within its narrow limits of 

 three hundred small pages no candid reader 

 would expect to find all the details that 

 might be wished for, or all the illustrations 

 that might be desired. What constitutes 

 the book's chief charm is the marvelously 

 simple yet quite scientific style which runs 

 through it, the food for thought and future 

 study which it affords, and the truly philo- 

 sophic glow which lights up its every page. 

 The volume gives a general account of Life's 

 Simplest Children, the Protozoa. The word 

 " slime " does not seem to us quite a happy 

 term by which to designate the living pro- 

 toplasm of these creatures ; this word con- 

 veys the idea of a something adhesive or 

 glutinous, or of a something thrown off a 

 living organism a something without a 

 structure (sordies, eluvies) and there seems 

 somewhat of a "contempt for nature," a 

 thought certainly never present in the au- 



