1022 The American Naturalist. [December, 
To us it seems as if the above plan, while admirable in some 
respects, was open to criticism. Polygordius, for instance, is a simple 
annelid, and whether that simplicity is primitive or results from degen- 
eration is of secondary moment in a text book of this sort. Our 
objection would rather rest upon the fact that the worm is not widely 
distributed and is infrequent, at least in American waters, while the 
inland student must entirely forego its use in his laboratory work. On 
the other hand it is well to have this presentation of the features of 
this simple worm, for it is usually slighted in our text books and in 
the most recent one, Hertwig’s Lehrbuch, it and the group to which 
it belongs are entirely ignored in the text. 
The numerous illustrations are, for the most part, original, and each 
plate is fully described instead of having appended a mere list of ref 
erence letters. A synopsis, an index, and a glossary complete the 
work. 
Apgar’s Trees of the Northern United States.’—The plan 
of this little book is well indicated in one of the paragraphs in the 
preface. The difficulty in tree study by the aid of the usual botanies 
lies mainly in the fact thatin using them the first essential parts to be 
examined are the blossoms and their organs. These remain on the 
trees a very short time, are often entirely unnoticed on account of 
their small size or obscure color, and are usually inaccessible, even if 
seen. In this book the leaves, the wood, the bark, and, in an elemen- 
tary way, the fruit, are the parts that must be thoroughly known by 
all who wish to learn to recognize trees. Its purpose is to place before 
pupils in the public schools an easy manual of our common trees 2 
the hope that the trees of our forests, lawns, yards, orchards, streets, 
borders, and parks may not continue to be neglected—a most com- 
mendable endeavor, indeed. : : : 
Doubtless if our teachers of botany in the public schools had any- 
thing like an adequate knowledge of the subject such a book would 
not be called for, but as Prof. Apgar somewhat sarcastically remarks, 
“ this book was written for the average teacher who has had no strictly 
scientific training.” It is to be hoped that it will serve the purpos® 
intended by its author, and that the next generation of high school 
graduates, all of whom have “done botany, of course,” will know 
*Trees of the Northern United States, their study, description and determination; 
for the use of schools and private students, by Austin C. Apgar, professor bug a 
in the New Jersey State Normal School. Small, 8 vol., 224 pp. American 
Company, 1892. i 
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