Why doesn't ssh module start crypto module?

[Matt Reynolds]

Am I misunderstanding the use of the "applications" atom in the
Applications configuration
(http://erlang.org/doc/design_principles/applications.html)?

Erlang R13B01 (erts-5.7.2) [source] [smp:2:2] [rq:2] [async-threads:0]
[kernel-poll:false]

Eshell V5.7.2  (abort with ^G)
1> application:start(ssh).
{error,{not_started,crypto}}

Does the "applications" configuration simply specify what must be
started first, without starting those modules?  So the Application
specifying dependencies must start it itself?  If so, why doesn't SSH
start crypto?