March ], I860.] 



HAHDWICKE'S SCIENCE-GOSSIP. 



flowers in the transient sunshine, and closes them 

 again under every passing cloud. It is found almost 

 everywhere on humid soils, in the laues and hedge- 

 rows, on the edge of coppices and among the grass ; 

 but it is on the banks of streams and watercourses, 

 where the tuberous roots can strike deep, that its 

 chief beauty is seen: there the star-like flowers, 

 resting on a bed of deep green foliage, are, in the 

 early season, conspicuously large and bright. 



Ere a leaf is on a bush, 



In the time before the thrush 



Has a thought about its nest, 



Thou wilt come with half a call, 



Spreading out thy glossy breast 



Like a careless prodigal, 



Telling tales about the sun 



When there's little warmth or none. 



So William Wordsworth addresses this flower of 

 his adoption : — 



There's a flower that shall be mine, 

 'Tis the little Celandine. 



It was near middle life with him before this poetic 

 attachment commenced, for which he seems to 

 reproach himself : — 



I have seen thee high and low 

 Thirty years or more, and yet 

 'Twas a face I did not know ; 

 Thou hast now, go where I may. 

 Fifty greetings in a day. 



And for well-nigh half a century afterwards it 

 cheeered his solitary musings by the waterfalls and 

 in the woods, and he " blessed it for fellowship." 



The sentiment survives the poet, in the memory 

 of his disciples and friends, in the congenial minds 

 which " make their own delights " in the calm pur- 

 suits of country life, and it is symbolized upon the 

 Laureate's tomb. Tourists to the Lake districts — 

 and there are many — who visit the churchyard and 

 church of Grassmere, when they read the epitaph 

 and do homage to the memory of departed worth 

 and genius, see a flower, with folded petals, 

 sculptured upon the white marble : it is the little 

 Celandine. S. S. 



ABOUT CILIA. 



TF we examine any one of those active little infu- 

 -*- sorial animalcules, millions of which are present 

 in every drop of ditch-water, we shall find that their 

 only organs of locomotion are certain hair-like pro- 

 cesses known as Cilia. 



These cilia are found more or less, with two or 

 three exceptions, in every class of the animal king- 

 dom. In some of the lowest forms of animal organi- 

 zation we meet with we find that they are of the 

 greatest possible use, serving as organs of locomo- 

 tion, or as a means of procuring food by creating 

 currents in the water; whilst in the higher animals — 

 the mammalia for instance— they serve a more sub- 



ordinate though no less useful office, that of con- 

 veying the mucus found in different parts of the 

 hody to openings, from which it may be easily ex- 

 pelled. They are found on the gills of the tadpole, 

 where they assist the respiration by causing the' 

 water to flow over the branchiee, on the surface of 

 the body of the Spongiadse, the Polypi, the Medusa?,, 

 and the Echinodermata, and also in the alimentary 

 system of many animals. The Unio and Aordon— 

 the common fresh-water mussels — which have no 

 prehensile or masticatory organs, are entirely depen- 

 dant for a supply of food, consisting principally of 

 infusoria, on the motion of the cilia lining the 

 mantle and the surface of the gills, which serves to 

 urge it forward to the region of the mouth. 



When in rapid motion they have the appearance 

 of a wave quickly passing over the surface to which 

 they are attached, reminding one of the action of ft 

 strong wind on a field of corn. They are seen much 

 more distinctly when the movement is somewhat 

 slackening than when they are in full activity. The 

 motion resembles that of an oar, and it has been 

 found that they can rotate on their axis through a 

 quarter of a circle, so that in the return stroke the 

 blade is parallel to the direction of motion. 



One of the most curious facts in connection with, 

 the subject is that the activity of the cilia does not 

 immediately cease on the extinction of the life of 

 the animal on which they are found, for their motion 

 has been observed in the tortoise for fifteen days 

 after death, when putrefaction was far advanced, 

 and in the frog for four or five days. The cause of 

 their motion has long been a debatable point among 

 naturalists ; but, as the motion is found after systemic 

 death, it is thought to be connected with the con- 

 tractile substance of which muscles are composed. . 

 If it does not depend upon this substance, it has 

 been argued it must be caused by some substance 

 of the nature of which we know nothing, and of the 

 very existence of which we have no proof, for our 

 most powerful microscopes have as yet been unable 

 to discover the motor power of these interesting 

 processes. It is, however, evident that that power, 

 whatever it may be, must be connected with each 

 cilium, for there can be no doubt that they move 

 individually, and without connection with their 

 neighbours, except as to the direction of their 

 motion. 



There are various external agencies, by the appli- 

 cation of which the movements of vibratile cilia may 

 be greatly modified or altogether arrested. In warm - 

 blooded animals a cold of 43° E. or under will per- 

 manently stop their motion, but in cold-blooded 

 animals they will bear a much greater degree of cold, 

 a mixture of ice and water having no apparent effect 

 on them. A gentle warmth, such as may be caused 

 by breathing on them, will in many animals revive 

 them after they have become languid. 



In many marine molluscs, such as the sea-mussel,. 



