646 



NATURE 



{Oct. 17, 1878 



tioned by Dr. Murie and Mr. Mivart in their paper upon 

 the anatomy of the Aye-aye, published in the Proceedings 

 of the Zoological Society. In examining the nervous 

 system of the cervical region arrangements were dis- 

 covered quite different from those seen in rodents. For 

 example, the trunk of the great sympathetic nerve, Avhich 

 is otherwise separated from the pneumogastric in the 

 whole extent of this region, has no middle cervical 

 ganglion, but only an inferior one, excessively reduced in 

 bulk. The superior cervical ganglion, situated imme- 

 diately above the bifurcation of the common carotid, 

 adheres by its fibrous sheath to the pneumogastric ; and 

 it is at this spot that the superior laryngeal nerve detaches 

 itself from the pneumogastric, crossing the ganglion with 

 Avhich it enters into connection. On the left side there is 

 no indication of a nervous filament answering to a 

 depressor nerve, while on the right there may be seen to 

 detach themselves from the superior laryngeal nerve two 

 filaments of excessive tenuity which go to rejoin the 

 trunk of the great sympathetic nerve. Nothing in this 

 arrangement suggests resemblance to the nervous cord 

 so distinct among the rodents, and above all among the 

 Leporidae, which, from this very circumstance, have fur- 

 nished physiologists with the opportunity of making 

 experiments of the greatest value. This character distin- 

 guishes the Aye-aye also from the opossums, which were 

 placed by lUiger with the apes and lemurs in his order 

 " Pollicata." The nervous arrangements, in short, con- 

 firm the results arrived at by the study of the muscles, 

 viscera, and organs of generation, of the external form, 

 skeleton, and dentition. J. C. G. 



Prof. Caruel's Classification of the Vegetable 

 Kingdom. — At the close of his recent work, " La Morfo- 

 logia Vegetale," Prof. Caruel of Pisa proposes a classi- 

 fication of the vegetable kingdom which has not so much 

 of novelty in its principles of classification as in its 

 terminology and the salient characters of the groups. 

 He makes the following five primary groups, viz. : — i. 

 Phanerogamia. Every individual is trimorphic. The 

 first form is neutral, and is capable of indefinite develop- 

 ment, and of organic reproduction, principally by means 

 of buds. This organic form gives rise, through the 

 medium of the flower, to the two other (sexual) forms, 

 male and female, which have only a definite development. 

 The male form or pollen is thalloid ; the female form or 

 gemmule (ovule) is cormoid ; this last produces, first, a 

 pro-embryo as the result of the fecundation by the fovilla 

 of the pollen, of an oosphere contained in a closed oogo- 

 nium, and finally, the embryo of the neutral form, which 

 develops at the extremity of the pro-embryo and in the 

 same direction. In the subdivision of Phanerogamia, 

 Caruel discards the distinction between Gymnospermia 

 and Angiospermia, retaining, as the two primary classes, 

 Monocotyledones and Dicotyledones, and giving the 

 higher rank to the former. 2. SchiSTOGAMIA, including 

 Characeae only. These are also trimorphic ; but the male 

 sexual form consists of vermiform phytozoa (anthero- 

 zoids) instead of pollen-grains, formed in an antherocyst 

 (antheridium) differing in structure from the anther ; the 

 female form consists of an oogemma (archegonium) com- 

 parable to a gemmule, but naked ; the neutral form 

 springs directly from the oospore, which, on germinating, 

 produces the embryo transversely. 3. Prothalloga- 

 MIA, or Vascular Cryptogams. These are also trimorphic 

 The neutral form does not produce the two sexual 

 forms, but spores ; these, on germinating, are trans- 

 formed into sexual prothallia, with archegonia and naked 

 oospheres, and vermiform phytozoa contained in anther- 

 idia ; the oospore gives rise transversely to the embryo 

 of the neutral form. The Prothallogamia are divided 

 into Heterosporae and Isosporas. 4. Bryogamia (syno- 

 nymous with Muscineae). The distinguishing character 

 of this group is the indefinite power of development of 

 the female individual, together with the definite develop- 



ment of the neutral form or sporogonium. A consequence 

 of this is the continued and repeated fecundation of 

 which the female form is capable, which distinguishes 

 the Bryogamia from the three preceding groups. The 

 embryo springs directly from the oospore ; the male 

 forms are phytozoa. The group is divided into Musci 

 and Hepaticae. 5. Gymnogamia (Thallophyta or Cel- 

 lular Cryptogams). The simplest Gymnogamia possess 

 only a single form, which is reproduced agamically by 

 fission, by conidia and sporidia, or by gamogenesis, but 

 without any sexual differentiation. In others there is 

 sexual differentiation into male and female forms ; a few 

 have also a third neutral form, when the oospore pro- 

 duces zoospores, instead of passing directly into the 

 female form. They resemble the Bryogamia in the de- 

 finite development of the neutral form and the indefinite 

 development of the female form, but differ in the 

 zoospore-like form of the phytozoa, and in the structure 

 of the oogonium, which is isolated and naked, and does 

 not form part of an archegonium. Prof. Caruel altogether 

 discards the old classification of Thallophytes into Algae, 

 Fungi, and Lichens, but does not propose any other in its 

 place, thinking it probable that, as our knowledge of 

 some of its forms increases, it will be broken up into 

 several primary groups He thinks it would be an advan- 

 tage if the term Cryptogamia were altogether disused. 



Transition Forms of Crinoids in American 

 Palaeozoic Rocks. — Messrs. C. Wachsmuth and F. 

 Springer have carefully studied the crinoids of the sub- 

 carboniferous rocks of the Mississippi valley, especially 

 the BurHngton and Keokuk limestones. There is pro- 

 bably no region in the world which exhibits, within the 

 same limited geographical extent, so great and uninter- 

 rupted a range of crinoidal deposits in geological succes- 

 sion, almost unaltered. These observers conclude that 

 extravagant forms and developments are not perpetuated, 

 and that types mostly cease to exist when they reach a 

 culmination in anatomical features. A large proportion 

 of the genera become extinct in the formations above 

 mentioned. The extinction of specific forms was not 

 coincident with the close of the respective epochs of 

 limestone deposits, but most of the changes were made 

 by a series of slow and gradual modifications of specific 

 characters, which correspond in a striking manner with 

 the changes in individual life by growth. The smaller 

 and less conspicuous forms Avere generally persistent, 

 and ranged through the whole crinoidal formations with 

 comparatively little change. 



GEOGRAPHICAL NOTES 



According to present arrangements, we believe that 

 Mr. Keith Johnston, the leader of the expedition which 

 the Committee of the African Exploration Fund are 

 about to despatch from the East Coast of Africa to Lake 

 Nyassa, will leave England on November 14 for 

 Zanzibar, together Avith his second in command, Mr. 

 Thomson, whose more especial function it will be to 

 study the geolog}' of the country traversed. Mr. Thom- 

 son, we believe, has had an excellent training as a 

 geologist, and it is expected that he will make important 

 contributions to our knowledge of the geology of the 

 region to be visited. The expedition v/ill not actually 

 start for the interior till next spring, and the interval 

 will no doubt be utilised in making short journeys 

 on the mainland, and in procuring all information pos- 

 sible in regard to the inhabitants, language, &c., of the 

 region Avhich is about to be thoroughly and scienti- 

 fically explored. We sincerely trust that Mr. Johnston 

 may not meet with the same trouble in the matter of 

 porters as has so long retarded the progress of the 

 Belgian and one or two other expeditions, but we do 

 not hear that the Royal Geographical Society have 

 formally given in their adhesion to the most recent 



