22 



square, thus causing less disturbance to the regularity of the 

 squares than happens in the Euplectella (see fig. 14). But this 

 is nor all the beauty and delicacy of the intimate structure of 

 the Ventriculidse. A structure remains to be described, to which 

 the expressions of Prof. Owen in describing the Euplectella may 

 well justify me in saying that no language can do justice, and 

 which no one can contemplate without delight, wonder, and 

 exquisite admiration. 



If the reader's attention has ever been attracted by the roofs 

 of the large railway stations, he will have perceived that they are 

 held together by the mutually counteracting and balancing effects 

 of thin rods obliquely placed any one of which would singly 

 be very inefficient for any substantial purpose. To give a barred 

 gate strength, or to keep a loose door or window-frame to its 

 true square, we see the carpenter fix a bar obliquely subtending 

 the right angle, which will hold the more securely the nearer it 

 is fixed to each side at equal distances from the angle. The prin- 

 ciple of the bracket which supports a shelf or bust is but the same. 



But there is nothing new under the sun. Ages before rail- 

 ways or carpenters existed, nature had adopted this very plan, to 

 give strength and stability to the deep ocean forms of the whole 

 family of Ventriculidse ; only, as she ever does, adopting a method 

 far more delicate, complete and beautiful than it were possible for 

 the hand of man to execute. 



I have said that the fibre is arranged in a tissue of regular 

 squares, which are formed by the anastomosing, at each angle, 

 of that fibre. But, besides these fibres, of which there necessa- 

 rily occur at each angle three entire ones crossing each other, or 

 six looking at them as radiating from the angle as a centre, these 

 crossing and anastomosing fibres are strengthened and secured by 

 twelve still finer oblique fibres, each about one-fourth of the length 

 of any one square itself. Each of these fibres subtends one of the 

 angles formed by two of the primary crossing fibres, and of which 

 angles there are of course at each crossing twelve. Each of them 

 anastomoses with one pair of the primary fibres in each position 

 in which they meet to form a right angle. This anastomosis 

 takes place at an equal distance on each primary fibre from the 

 angle itself, namely, at a distance of about one-fifth of the length 

 of one side of the square. Thus it will be seen that at each 

 place of crossing there are twelve subtending fibres and six pri- 

 mary fibres, in all eighteen fibres. Now, taking a Ventriculite 

 of very moderate size, say three inches in height and plain, we 

 shall have a membrane containing at least 750,000 squares, and 

 at least nine million of these delicate subtending fibres, each 

 faultless. What a marvellous piece of workmanship is this ! 



It will be perceived that by this most admirable contrivance a 



