270 Likenesses ; or, Philosophical Anatomy 



branches, that, in his opinion, ' no definite answer can be 

 given' to the question whether the trabeculse 'grow into 

 adjacent tissues, as a tree pushes its roots into the soil,' or 

 whether their apparent extension does not * arise rather from 

 a chondrification of the pre-existing tissue in the immediate 

 neighbourhood of the trabecular cartilage ? ' 



Secondly, when ossification begins to set in, the meaning 

 of the several ossific centres as they arise must be inter- 

 pretated by their later stages, or subsequent adult conditions 

 in the same animal or in other animals. How else could 

 epiphyses ever be discriminated from other ossific centres ? 

 Again, the circumstance of a bone or cartilage making its 

 appearance as a single element may in any case be due to 

 the junction of its incipiently distinct parts at a period 

 anterior to possible observation — in other words, it may be 

 made up of parts which are called connate — Le. never 

 distinct to observation, though judged from analogy to 

 be essentially multiple. Of such rationally inferred but 

 invisible distinctness botany offers us a multitude of ex- 

 amples. The stages passed through by the larvae of moths 

 and butterflies throw but a doubtful light on their adult 

 condition ; and what misleading ideas might not be sug- 

 gested by the development of the Sitaris beetle ? This 

 insect, instead of at first appearing in its grub stage, and 

 then after a time putting on the adult form, is at first active 

 and furnished with six legs, two long antennae, and four eyes. 

 Hatched in the nests of bees, it at first attaches itself to one 

 of the males, and then crawls, when an opportunity offers, 

 upon a female bee. AVhen the female bee lays her eggs, the 

 young Sitaris springs upon them and devours them. Then, 

 losing its eyes, legs, and antennae, it sinks into an ordinary 

 grublike form, and feeds on honey, ultimately undergoing 

 another transformation, re-acquiring its legs and antennae, 

 and emerging a perfect beetle. Surely the results of develop- 



