- 



RED SNOW. 



REPRODUCTION IN PLANTS AND ANIMALS. 



salt, and gypsum, but few or no organic remains. The prevalence of 

 red-oxide of iron in any of the strata is accompanied by a paucity or 

 total absence of organic remains. In the new red-sandstone these 

 red strata extend through several hundred feet of thickness, and it is 

 found in general terms, that the types of organic life above and below 

 are widely different. Similarly the thick series of old red-sandstone 

 contains few organic fossils, and separates two distinct groups of these 

 productions. Some great physical changes then must be supposed to 

 have occurred previous to and during the saliferous period, and to have 

 influenced both chemical and vital phenomena. 



M. Adolphe Brongniart (' Prodrome d'une Histoire des Ve'ge'taux 

 Fossiles," 1829), viewing the series of fossil plants, gives four great 

 periods of ancient vegetation : The first extending from the earliest 

 strata to the new red-sandstone strata ; the second including these 

 strata ; the third including the oolites and chalk ; the fourth the 

 tertiary strata. Of these the flora of the second period (chiefly ter- 

 restrial) is very limited, and may be looked upon as a transition group 

 of plants connecting the earlier and later periods. Similarly the series 

 of marine Invertebrata which lie in the new red-sandstone have 

 characters intermediate between the early (palaeozoic) and later races 

 of pre-adamitic life. 



i' Although the fossils of this rock are but few, they are highly 

 interesting. It is amongst these rocks that we find the first traces of 

 an air-breathing animal This creature, which was at first called 

 Chirotkeum, is now known under the name of Labyrinthodon. It 

 belongs to the amphibious tribe of Reptiles. [AMPHIBIA.] Foot- 

 marks of an extinct reptile have also been found in the red-sandstone 

 of America, and described by Dr. Lea. [SATJROPUS.] 



The equivalents of the British beds of new red-sandstone on the 

 continent of Europe are the Kauper Marls, or Marres irise'es, the 

 Muschelkalk, and the Bunter Sandstein, or Ores Bigarre, of Germany 

 and France. 



RED SNOW. [SNOW, RED.] 



REDPOLE [LIXOTA.] 



REDSTART. [SYLVIAD.E.J 



RED-WING. [MERULID.E.] 



REED. [PlIRAGMITES.] 



REED, SEA. [PSAMSIA.] 



REED-BUNTING. [EMBERIZIO.K.] 



REED-BUK. [SPAROANICM.] 



KEED-MACE. [TYPIIA.] 



REED-WARBLER. [SALICARIA.J 



REED-WREN. [SAUCARIA.] 



REGENIA. [MONITORID.E.J 



REGULUS. [Coc-KATFiicE.] 



REGULUS, a geuus of Birds belonging to the family Sylviada. 

 The genus is thus defined by Mr. Yarrell : Beak slender, straight, 

 the edges dilated at tho base, compressed towards the point; nostrils 

 basal, lateral, oval, partly covered by small feathers directed forwards. 

 Wings of moderate length ; the first quill-feather very short ; the 

 second shorter than the third ; the fourth or fifth the longest in the 

 wing. Legs rather slender; feet with three toes before, one behind ; 

 the outer toe joined at its base to the middle toe ; claws curved and 

 sharp. There are three British species of this genus. 



R. crittattu, the Golden-Crested Regulus, Golden-Crested Warbler, or 

 Kinglet. 



It. (ijnicapillia, the Fire-Crested Regulus, Fire-Crested Wren. 



R. modestiu. the Dalmatian Regulus. This is a very rare species. 



There are three other species natives of North America. 



(Yarrell, British Birdi.) 



REH BOC. [CERVID.K.] 



REIN-DEER. [CERVIIJ.K.] 



REIN-DEER MOS3. [CLADOHIA.] 



REMAINS, ORGANIC. [ORGANIC REMAINS.] 



REMBUS. [Licisos.] 



UEMIPES. [HIPPIDES.] 



REMOPLEU'RIDES, a singular fossil genus of Trilobitei found in 

 the Silurian Strata of Tyrone by Portlock, who describes it in his 

 'Geological Report" on Tyrone. 



REMORA. [EcHENEis.] 



REPRODUCTION IN PLANTS AND ANIMALS. "The term 

 Reproduction has been employed to denote those processes in organic 

 beings by which the individual being is produced, developed, and 

 maintained. It has thus been employed to express processes which 

 are functionally distinct, and have very different ends in the economy 

 of creation. The constant reproduction of the same tissues in the 

 .ame part, is the means by which the form of the individual being is 

 maintained during its life, and is the result of the ordinary processes 

 of nutrition. This function is carried on throughout the whole 

 animal and vegetable kingdom, until the death of a part or the whole 

 of the being occurs. The power however of reproducing the same 

 tissues, varies in different beings, and we find that although it is 

 possessed even to the restoration of a lost limb amongst the lower 

 animals, no inch power is possessed by the highest. 



The term Reproduction has also been applied to the origination of 



rrn from which individual plants and animals grow. The process 



employed in the initiation of life, seems to be essentially distinct from 



engaged in carrying it on : hence the propriety of distinguishing 



in terms between that production of cells by which the life of the 

 individual is maintained, and the arrangements by which its existence 

 as an individual is ensured. It has been proposed to restrict the 

 term Generation to the latter process. 



Although formerly great difficulties existed in distinguishing between 

 these two processes from the want of sufficient observations, recent 

 researches seem to have supplied all that is necessary. In the 

 ordinary reproduction of the tissues of plants and animals each cell 

 has the power of producing other cells, or a large number of the same 

 kind of cells are developed simultaneously, but ia generation it i* 

 necessary that two cells should take part. At one time it was supposed 

 that this process did not take place in the generation of the lower 

 animals and plants, but recent investigations have shown that the 

 union of two cells is necessary to so large a number of the forms of 

 lower plants and animals, that it is a fair inference that this ia a' 

 universal necessity in the generation of organic beings. The two 

 cells thus engaged have been called the germ-cell and the sperm-cell. 

 The germ-cell is that in which the process of growth of the new 

 being commences, whilst the sperm-cell is that whch communicates 

 the growing tendency to the other. These cells are of different sizes 

 and forms in the animal and vegetable kingdoms, and are placed in 

 very various positions in relation to other organs, and the means by 

 which they are brought together are very various, but in all eases thoy 

 perform the same fundamental function. 



The discovery of the necessity of the union of these two cells, for 

 the production of a new being, has gone far to settle the question of 

 " equivocal " or " spontaneous generation." Ever since the extended 

 use of the microscope in the investigation of the structure of tha 

 organic being^ it has become more and more apparent that there was 

 no basis for the supposition that organic beings came into existence 

 independent of a preceding organism. The only cases in which it is 

 now pretended that such an origin of organic life could take place, 

 are those in which the minuter forms of animal and vegetable life 

 occur in infusions exposed to the atmosphere. But this occurrence 

 admits of easy explanation, when it is remembered how exceedingly 

 minute many of these organisms are, and that they are frequently 

 produced from ova much smaller than themselves. Such organisms 

 are easily taken up into the atmosphere, and can be thus conveyed 

 from one spot to another. That such is the fact is proved by the 

 experiment of passing atmospheric air through red hot tubes or strong 

 sulphuric acid, when it is found that water exposed to such air never 

 affords any indications of the existence of organic bsings, whilst the 

 same water exposed to ordinary atmospheric air will, in a few hours, 

 teem with living beings. 



Although the subject of the generation of animals and plants has 

 been regarded as a subject of much mystery, the facts it presents are 

 now as well understood as any other branch of physiological inquiry. 

 The greatest mystery is the mystery of all nature, and that is the 

 reason of the assumption of a particular form by what appears to be 

 the same combination of elements. No difference can be discerned 

 in the cells of the flowers of the oak and the apple, but the one 

 always produce oak-trees, whilst the others always produce apple- 

 trees. It is the same witli the cells of animals, without the slightest 

 appreciable external difference ; the one set of cells will develop the 

 form of one species of animal, and another set, another species. This 

 fact has led some inquirers to the assumption of the existence of a 

 ' vital principle,' of a distinct and independent essence giving to each 

 species its definite form and character. There is no objection to such 

 an hypothesis, provided it is not made use of to explain phenomena 

 which are clearly under the influence of chemical and physical forces. 

 As so much misunderstanding prevails with regard to the word 

 ' vital principle," it is better perhaps to discard it, and to speak of 

 the limitation of form to which each species is subject, as under the 

 control of a ' formative force.' This formative force being the 

 ultimate fact in the history of each individual plant and animal, and 

 regulating the chemical and physical processes, the result of which is 

 usually called life, it has been proposed to call this a germ-force, or 

 a germinal capacity ; but as it is very clear that it is the same force 

 that ia in action to produce the whole lifa or growth of tho plant or 

 animal, there is no necessity for distinguishing its first effects, as 

 observed in the act of generation. 



In studying then the phenomena of generation, there are three con- 

 ditions which have to be regarded. 



Firstly, the Formative Force, which is peculiar in every species, and 

 identical in all the generative cells produced in that species. 



Secondly, the Physical Conditions in which the generative cells aro 

 placed. These are more especially heat and light, and the condition 

 of the cell-membrane through which absorption takes place. 



Thirdly, the Elements which are supplied for the nourishment of 

 the new being, and which by their Chemical Properties are capable of 

 exercising an influence on the form and development of the plant or 

 animal. 



Each of these circumstances is found exercising varying degrees of 

 influence in plants and animals. Thus, amongst the lower forms of 

 both the animal and vegetable kingdom, the formative force appears 

 to exercise less influence than among the higher. This is seen in the 

 very varied forms which the same species of plant and animal assume 

 under different circumstances. In fact, till very recently, many of the 



