82 SOME CURIOUS FACTS CONNECTED WITH 



the habits of a most insignificant looking worm-Uke animal, 

 Feripatus, and in the Cambridge lecture rooms, this creature is 

 the observed of all observers. Why ? Because in Feripatus is 

 found a link between worms and arthropods. Hatter-ia, a lizard 

 of very ancient type, has long possessed a similar interest, now 

 intensified through the recent discovery which shows the unques- 

 tionably invertebrate descent of this vertebrate animal. I will 

 quote an extract on the subject from the Contemporary Review for 

 October, premising that fully equal honour is due to the German, 

 as to the English discoverer. The Englishman was simply bolder 

 in publishing his discovery. 



" One genus alone is extant of the lizard-like reptiles known 

 as RhyncJwcephalia (from their beak-like, horny mouths). This 

 genus comprises only the Hatteria of New Zealand. Mr. Spencer, 

 of Oxford, whilst engaged in studying the anatomy and histology 

 of this animal, found a curious sense organ buried in the 

 substance occupying the parietal foramen [the suture at the top, 

 across the middle of the skull]. This sense organ was placed on 

 what is known as the pineal body, the function of which has been 

 hitherto unknown. This pineal body arises from the roof of the 

 third ventricle [or fore brai?i of embryologists], and in both 

 Amphibia and Reptilia becomes divided into two parts, one 

 retaining connection with the brain, and the other, a bladder- 

 shaped structure, which is usually completely separated from the 

 former. In Angus fragilis [a degenerate lizard commonly known 

 as the blind worm] this bladder-shaped structure resembles a 

 highly-organised invertebrate eye, hut without afiy nerve. In 

 Hatteria this portion also becomes an eye, but an eye provided 

 with a 7iiell-marked nerve. This eye is simple, lying exactly in the 

 middle line, under the parietal foramen, an aperture at the 

 anterior end of the median suture of the parietal bones. A 

 depression of the skin of the head occurs immediately over this 

 parietal foramen, but does not lead down into this, which is filled 

 up with a plug of connective tissue, which is specially dense 

 round the capsule that envelopes the eye. The capsule is also 

 filled up behind with connective tissue, in which a blood vessel, 

 entering with the nerve, divides and ramifies. The nerve is single. 

 It is palpably a well-constructed invertebrate eye — the eye of an 



