March i8, 1909] 



NA TURE 



are met with among fungi, as in Mttcor racemosus, 

 possibly among Bryophyta, and in one or two gym- 

 nosperms. A considerable number of angiosperms 

 have been recorded as producing embryos otherwise 

 than from the fertilised ova, but in a large propor- 

 tion of cases doubt exists as to the true origin of 

 such embryos and as to the behaviour of their chromo- 

 somes, while other reported cases are much in need 

 of re-investigation of the alleged facts. 



Having set aside all doubtful cases, there remain 

 several in which the whole course of formation of 

 the new individual has been followed out and made 

 known in its details. Apogamy was first studied in 

 the outgrowth of a fern plant directly from the pro- 

 thallus. Occurring in certain varieties of different 

 species, the details of the process have been found 

 to differ widely; e.g. pseudomixis prevails in 

 Lastrca pseiidomas, var. polydactyla ; somatic apo- 

 gamv in Athyrium Filix-foeiniiia, var. clarissima, 

 and generative apogamy in Nephrodium mollc. 

 Somatic apogamv is not common among phanerogams, 

 but has been shown to occur in .HcheDiilla scricata, 

 one of the helper-cells giving rise to an embryo along 

 with the parthenogenetic ovum, while in Balanophora 

 Aonf^ata somatic apogamy leads to an embryo being 

 formed from a cell of endosperm. 



Generative apogamy is illustrated in the develop- 

 ment of embryos from antipodal cells in Allium 

 odorum, but it also is in want of further study among 

 phanerogams. 



Generative parthenogenesis has been observed 

 among a few algae (Spirogyra mirabilis, Cosmarium 

 Botrytis, &c.), chiefly under artificial stimuli, and 

 possibly also among fungi, but not among other 

 plants. Somatic parthenogenesis, on the other hand, 

 has not been proved to exist among the purely cellu- 

 lar plants, while it has been met with in true ferns 

 U'.g. .ith. Filix-foemina, var. clarissima) and Mar- 

 silia Drummondii, and in several dicotyledons, espe- 

 cially among Compositae (.Anteiiiiaria alpina and other 

 species. Taraxacum, sps., Hieracium, sps.), in .U- 

 chemiUa, sps., in Thalictnim, sps., Sec. In all these 

 flowering plants the pollen of the parthenogenetic 

 species is ill-developed or useless. Parthenocarpy or 

 the formation of apparently fully developed fruits 

 from unpoUinated or unfertilised carpels is a well- 

 known fact, especially among cultivated plants, and 

 has led not infrequently to the assumption of 

 parthenogenesis, but in these cases the fruits are 

 often sterile, as in bananas and other seedless fruits. 



The latter part of the monograph is devoted to 

 such speculative questions as whether the partheno- 

 genetic ovum is a somatic or a truly generative cell ; 

 whether apogamy and parthenogenesis lead to the 

 suppression of alternation of generations in plants 

 in which it normally exists; the origin and mutual 

 relations in the cycle of the haploid and diploid 

 types of cells; and the possible advantages of their 

 intercalation in the cycle ; the causes and explana- 

 tions of parthenogenesis and apogamy, and the in- 

 formation on these derived from experiments. The 

 discussion of these topics is suggestive and full of 

 interest, but the reader must be referred to the work 



NO. 2055, VOL. 80] 



itself, as it is not possible to summarise fairly the 

 views stated. It may be said that there is still 

 much to be done before the way is clear. 



The biological value to plants of parthenogenesis 

 and apogamy is evidently, like that of increase by 

 tubers, stolons, bulbs, and other purely vegetative 

 methods, the multiplication of the species by seeds, or 

 other readily dispersed bodies, in which the embryo 

 is produced without dependence on access of male 

 cells, whether sperms or pollen-nuclei, thus securing 

 the reproduction even from isolated female plants. 

 The disappearance of the pollen-bearing plants in 

 habitually parthenogenetic species is regarded as a 

 consequence, instead of as the cause, of partheno- 

 genesis. It has been observed that among the 

 genera that show the most marked tendency to this 

 condition are several (Hieracium, .Alchemilla, &c.) 

 peculiarly rich in closely allied forms, regarded by 

 some as species, by others as varieties ; but, on the 

 other hand, other polymorphic genera (Rubus, &c.) 

 show sexual reproduction of the normal kind. There 

 are very evidently many problems in these and other 

 fields relating to protoplasm still waiting to reward 

 research. 



ADMISSIONS OF AN ANTI-VIVISECTIONIST. 

 The Vivisection Controversy. Essays and Criticisms. 

 By Dr. Albert Leffingwell. Pp. vi-l-251. (London : 

 The London and Provincial Anti-vivisection Society, 

 1908.) Price 6s. 



DR. ALBERT LEFFINGWELL is an American 

 doctor who, as we gather from his title-page, 

 has written on the " Morality of London " and on 

 " Rambles in Japan without a Guide"; and who, 

 " having witnessed experiments on animals by some 

 of the most distinguished European physiologists, 

 such as Claude Bernard, Milne Edwards and Brown 

 Sequard, began to contrfbute to the vivisection con- 

 troversy twenty-eight years ago." He is contributing 

 still, and he is no exception to the rule that when 

 an anti-vivisectionist arrives at the controversial 

 stage the impression he makes on a logical mind is 

 not a favourable one. That is because anti-vivisec- 

 tionists, by addressing themselves continually and 

 solely to audiences of convinced sentimentalists, ac- 

 quire the habits of rhetoric and over-statement, and 

 become incapable of stating any fact regarding the 

 use of animals in experiment except in a controversial 

 relation. Thus Dr. Leflnigwell will not allow to experi- 

 ments on animals any of the credit for antiseptic or 

 aseptic methods in surgery ; he denies, as most anti- 

 vivisectionists do, any reduction in diphtheria mor- 

 tality, or virulence, by the use of antitoxin ; he mini- 

 mises, so far as he can, the use of antitetanus and 

 antivenous serums. He says nothing about bacterio- 

 logical research in plague, typhoid, Malta-fever, 

 or malaria ; but that is partly because the bulk of his 

 essays were published before those researches were 

 undertaken. It is also because the essays are filled 

 so largely with appeals to the emotions, with quota- 

 tions from Mrs. Barrett Browning's " Cry of the 

 Children'" and with long references to the iniquities 

 of the slave trade, that there is very little room even 



