Botany and Zoology. 77 



attempt their complete co-ordination, but it is not too soon to 

 predict that materials will before long be sufficient for a rational 

 discussion of many obscure points in Toxicology and, we dare to 

 hope, in Therapeutics. To the energy and carefulness with which 

 Dr. True has prosecuted his work thus far, we owe most import- 

 ant contributions, and we trust he will be encouraged to carry 

 his researches still further afield. The new paths which he has 

 been instrumental in opening up are likely to attract many 

 explorers. It is to be sincerely wished that all who enter the 

 new field will bring to the work the same acuteness, patience, and 

 thoroughness which seem to characterize the work thus far. To 

 those of our readers who may like to know the thought which 

 inspires the work, we may use words of Dr. True, which are 

 abundantly justified. " The application of the theory of dissocia- 

 tion of electrolytes, to explain the toxic action of acids, bases, and 

 salts, on living organisms has yielded results of greatest import to 

 both chemistry and biology." Now beyond these substances 

 others are to be investigated by the same methods : let us hope 

 with equally satisfactory results. g. l. g. 



2. On the peculiar mode of formation of pollen-grains in 

 Magnolias. — In the number of Comptes Rendus for Oct. 24, 1898, 

 Guignaed gives an extremely interesting account of one of the 

 puzzling exceptions to general rules, which are full of suggestions 

 as to classification of organisms. 



The author calls attention to the general characters of pollen 

 formation which serve to separate more or less completely mono- 

 cotyledons from dicotyledons. In the former, the first division of 

 the nucleus of the mother-cell is followed by partition of the lat- 

 ter, and then the two daughter-cells divide in their turn, in the 

 same way. In dicotyledons, on the other hand, the first nuclear 

 division is not followed by partition of the mother-cell ; that does 

 not take place until after the second nuclear division, between the 

 four nuclei which it has furnished. 



Now to this general rule, Guignard had already pointed 

 out a remarkable exception, namely, that among the monocoty- 

 ledons are to be found plants which behave in this respect 

 just as do the dicotyledons. These exceptions are the Orchid- 

 aceoe. They nearly all undergo simultaneous quadripartition of 

 the pollinic mother cell. The author now announces that in the 

 Magnolias is to be seen a type of division unlike either the 

 first or the second. The type is almost intermediate between 

 the two hitherto recognized, but by the formation of an incom- 

 plete partition (possibly sometimes complete) immediately after 

 the first nuclear bipartition, is more like that of the monocotyle- 

 dons than of the dicotyledons. g. l. g. 



3. Elements de JBotanique. P. Van Tieghem. 2 volumes, 

 16mo. Paris, 1898. — In this revised edition of a helpful work, 

 Professor Yan Tieghem gives his own views regarding certain 

 disputed points relative to structure, and states his reasons for 

 suggesting a new classification of the higher plants. The princi- 



