14 
Walter Frank Raphael Weldon. 1860—1906. 
and from this book as source spring two of the friendships and the whole of the 
biometric movement, which so changed the course of his life and work. In 1889, 
the year of the issue of this book, another change also came. Weldon found that 
his dredging and collecting work separated him from his books for half his time. 
Accordingly, he applied for a year's leave from Cambridge, and the Weldons settled 
down in a house of their own at Plymouth. This period of hard work lasted through 
1890, and was broken only by flying visits to Dresden in September and at 
Christmas, 1889, and an autumn visit in 1890 to Charfcrcs and Bourges. The 
intellectual development and the experience and knowledge gained in this period 
were far more important than the mere published work would indicate. In 1889, 
Weldon investigated the nature of the curious enlargement of the bladder 
associated with the green, or excretory, glands in certain Decapod Crustacea, 
and published in October of the same year his paper on " The Coelom and 
Nephridia of Palaemon servatus" (10). The result of his investigation was to 
confirm " the comparison so often made (by Claus, Grobben, and others) between 
the glomerulus of the vertebrate kidney and the end-sac of the Crustacean green 
gland." A little later, June 1891, Weldon published the results of more extended 
researches in this field in what proved to be his last strictly morphological paper. 
It was entitled: "The Renal Organs of certain DecajDod Crustacea" (11). In 
this he showed that in many Decapods spacious nephro-peritoneal sacs "should 
be regarded rather as enlarged portions of the tubular system. . .than as 
persistent remnants of a ' coelomic ' body cavity into which the tubular nephridia 
open." 
One further paper of a year later may be best referred to here, W^eldon's only 
piece of work on invertebrate embryology, "The Formation of the Germ Layers in 
Crangon vulgaris" (12). This contains a clear account of the early stages of 
segmentation and the building up of the layers of the shrimp, illustrated by 
excellent figures. And here it may be mentioned that Weldon's power with the 
pencil was not that of the mere draughtsman, accurate in detail, but too often 
lifeless. Weldon was an artist by instinct, and he had the keenest pleasure in 
drawing for its own sake. His brilliant blackboard drawings will be remembered 
by all his students ; some correspondents will remember elaborately beautiful 
sketches sent merely to illustrate a passing question, where a rough diagram would 
have sufficed ; a delicately pencilled shell to please a child frienH ; carefully copied 
architectural details to gratify himself and made to be destroyed ; — all signs of a 
real artistic power of creation. And the sense he enjoyed in himself, he 
appreciated in others. Nothing refreshed him so much as a visit to the National 
Gallery, or to a lesser extent the sight of more modern art. Weldon, smiling 
before one of his own pictures, unconscious of his environment, was good to 
behold, and made one realise how for him pictures were still differentiated from 
furniture. In the last two years of his life, when he had become an ardent 
photographer, the artistic feeling came to play a prominent part as the difficulties 
of the craft were one by one mastered. 
